Indian mathematics emerged in theIndian subcontinent[1] from 1200 BCE[2] until the end of the 18th century. In the classical period of Indian mathematics (400 CE to 1200 CE), important contributions were made by scholars likeAryabhata,Brahmagupta,Bhaskara II,Varāhamihira, andMadhava. Thedecimal number system in use today[3] was first recorded in Indian mathematics.[4] Indian mathematicians made early contributions to the study of the concept ofzero as a number,[5]negative numbers,[6]arithmetic, andalgebra.[7] In addition,trigonometry[8]was further advanced in India, and, in particular, the modern definitions ofsine andcosine were developed there.[9] These mathematical concepts were transmitted to the Middle East, China, and Europe[7] and led to further developments that now form the foundations of many areas of mathematics.
Ancient and medieval Indian mathematical works, all composed inSanskrit, usually consisted of a section ofsutras in which a set of rules or problems were stated with great economy in verse in order to aid memorization by a student. This was followed by a second section consisting of a prose commentary (sometimes multiple commentaries by different scholars) that explained the problem in more detail and provided justification for the solution. In the prose section, the form (and therefore its memorization) was not considered so important as the ideas involved.[1][10] All mathematical works were orally transmitted until approximately 500 BCE; thereafter, they were transmitted both orally and in manuscript form. The oldest extant mathematical document produced on the Indian subcontinent is the birch barkBakhshali Manuscript, discovered in 1881 in the village ofBakhshali, nearPeshawar (modern dayPakistan) and is likely from the 7th century CE.[11][12]
A later landmark in Indian mathematics was the development of theseries expansions fortrigonometric functions (sine, cosine, andarc tangent) by mathematicians of theKerala school in the 15th century CE. Their work, completed two centuries before the invention ofcalculus in Europe, provided what is now considered the first example of apower series (apart from geometric series).[13] However, they did not formulate a systematic theory ofdifferentiation andintegration, nor is there any evidence of their results being transmitted outsideKerala.[14][15][16][17]
Excavations atHarappa,Mohenjo-daro and other sites of theIndus Valley civilisation have uncovered evidence of the use of "practical mathematics". The people of the Indus Valley Civilization manufactured bricks whose dimensions were in the proportion 4:2:1, considered favourable for the stability of a brick structure. They used a standardised system of weights based on the ratios: 1/20, 1/10, 1/5, 1/2, 1, 2, 5, 10, 20, 50, 100, 200, and 500, with the unit weight equaling approximately 28 grams (and approximately equal to the English ounce or Greek uncia). They mass-produced weights in regulargeometrical shapes, which includedhexahedra,barrels,cones, andcylinders, thereby demonstrating knowledge of basicgeometry.[18]
The inhabitants of Indus civilisation also tried to standardise measurement of length to a high degree of accuracy. They designed a ruler—theMohenjo-daro ruler—whose unit of length (approximately 1.32 inches or 3.4 centimetres) was divided into ten equal parts. Bricks manufactured in ancient Mohenjo-daro often had dimensions that were integral multiples of this unit of length.[19][20]
Hollow cylindrical objects made of shell and found atLothal (2200 BCE) andDholavira are demonstrated to have the ability to measure angles in a plane, as well as to determine the position of stars for navigation.[21]
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The texts of theVedic Period provide evidence for the use oflarge numbers. By the time of theYajurvedasaṃhitā- (1200–900 BCE), numbers as high as1012 were being included in the texts.[2] For example, themantra (sacred recitation) at the end of theannahoma ("food-oblation rite") performed during theaśvamedha, and uttered just before-, during-, and just after sunrise, invokes powers of ten from a hundred to a trillion:[2]
Hail tośata ("hundred,"102), hail tosahasra ("thousand,"103), hail toayuta ("ten thousand,"104), hail toniyuta ("hundred thousand,"105), hail toprayuta ("million,"106), hail toarbuda ("ten million,"107), hail tonyarbuda ("hundred million,"108), hail tosamudra ("billion,"109, literally "ocean"), hail tomadhya ("ten billion,"1010, literally "middle"), hail toanta ("hundred billion,"1011, lit., "end"), hail toparārdha ("one trillion,"1012 lit., "beyond parts"), hail to theuṣas (dawn), hail to thevyuṣṭi (twilight), hail toudeṣyat (the one which is going to rise), hail toudyat (the one which is rising), hailudita (to the one which has just risen), hail tosvarga (the heaven), hail tomartya (the world), hail to all.[2]
Fractions are mentioned, as in the Purusha Sukta (RV 10.90.4):
With three-fourths Puruṣa went up: one-fourth of him again was here.
TheSatapatha Brahmana (c. 7th century BCE) contains rules for ritual geometric constructions that are similar to the Sulba Sutras.[22]
TheŚulba Sūtras (literally, "Aphorisms of the Chords" inVedic Sanskrit) (c. 700–400 BCE) list rules for the construction of sacrificial fire altars.[23] Most mathematical problems considered in theŚulba Sūtras spring from "a single theological requirement",[24] that of constructing fire altars which have different shapes but occupy the same area. The altars were required to be constructed of five layers of burnt brick, with the further condition that each layer consist of 200 bricks and that no two adjacent layers have congruent arrangements of bricks.[24]
According to Hayashi, theŚulba Sūtras contain "the earliest extant verbal expression of thePythagorean Theorem in the world, although it had already been known to theOld Babylonians."
The diagonal rope (akṣṇayā-rajju) of an oblong (rectangle) produces both which the flank (pārśvamāni) and the horizontal (tiryaṇmānī) <ropes> produce separately."[25]
Since the statement is asūtra, it is necessarily compressed and what the ropesproduce is not elaborated on, but the context clearly implies the square areas constructed on their lengths, and would have been explained so by the teacher to the student.[25]
They contain lists ofPythagorean triples,[26] which are particular cases ofDiophantine equations.[27] They also contain statements (that with hindsight we know to be approximate) aboutsquaring the circle and "circling the square."[28]
Baudhayana (c. 8th century BCE) composed theBaudhayana Sulba Sutra, the best-knownSulba Sutra, which contains examples of simple Pythagorean triples, such as:(3, 4, 5),(5, 12, 13),(8, 15, 17),(7, 24, 25), and(12, 35, 37),[29] as well as a statement of the Pythagorean theorem for the sides of a square: "The rope which is stretched across the diagonal of a square produces an area double the size of the original square."[29][30] It also contains the general statement of the Pythagorean theorem (for the sides of a rectangle): "The rope stretched along the length of the diagonal of a rectangle makes an area which the vertical and horizontal sides make together."[29] Baudhayana gives an expression for thesquare root of two:[31]
The expression is accurate up to five decimal places, the true value being 1.41421356...[32] This expression is similar in structure to the expression found on a Mesopotamian tablet[33] from the Old Babylonian period (1900–1600BCE):[31]
which expresses√2 in the sexagesimal system, and which is also accurate up to 5 decimal places.
According to mathematician S. G. Dani, the Babylonian cuneiform tabletPlimpton 322 written c. 1850 BCE[34] "contains fifteen Pythagorean triples with quite large entries, including (13500, 12709, 18541) which is a primitive triple,[35] indicating, in particular, that there was sophisticated understanding on the topic" in Mesopotamia in 1850 BCE. "Since these tablets predate the Sulbasutras period by several centuries, taking into account the contextual appearance of some of the triples, it is reasonable to expect that similar understanding would have been there in India."[36] Dani goes on to say:
As the main objective of theSulvasutras was to describe the constructions of altars and the geometric principles involved in them, the subject of Pythagorean triples, even if it had been well understood may still not have featured in theSulvasutras. The occurrence of the triples in theSulvasutras is comparable to mathematics that one may encounter in an introductory book on architecture or another similar applied area, and would not correspond directly to the overall knowledge on the topic at that time. Since, unfortunately, no other contemporaneous sources have been found it may never be possible to settle this issue satisfactorily.[36]
In all, threeSulba Sutras were composed. The remaining two, theManava Sulba Sutra composed byManava (fl. 750–650 BCE) and theApastamba Sulba Sutra, composed byApastamba (c. 600 BCE), contained results similar to theBaudhayana Sulba Sutra.
The Vedic period saw the work of Sanskrit grammarianPāṇini (c. 520–460 BCE). His grammar includes a precursor of theBackus–Naur form (used in the descriptionprogramming languages).[37]
Among the scholars of the post-Vedic period who contributed to mathematics, the most notable isPingala (piṅgalá) (fl. 300–200 BCE), amusic theorist who authored theChhandasShastra (chandaḥ-śāstra, also Chhandas Sutrachhandaḥ-sūtra), aSanskrit treatise onprosody. Pingala's work also contains the basic ideas ofFibonacci numbers (calledmaatraameru). Although theChandah sutra has not survived in its entirety, a 10th-century commentary on it by Halāyudha has. Halāyudha, who refers to the Pascal triangle asMeru-prastāra (literally "the staircase to Mount Meru"), has this to say:
Draw a square. Beginning at half the square, draw two other similar squares below it; below these two, three other squares, and so on. The marking should be started by putting1 in the first square. Put1 in each of the two squares of the second line. In the third line put1 in the two squares at the ends and, in the middle square, the sum of the digits in the two squares lying above it. In the fourth line put1 in the two squares at the ends. In the middle ones put the sum of the digits in the two squares above each. Proceed in this way. Of these lines, the second gives the combinations with one syllable, the third the combinations with two syllables, ...[38]
The text also indicates that Pingala was aware of thecombinatorial identity:[39]
Kātyāyana (c. 3rd century BCE) is notable for being the last of the Vedic mathematicians. He wrote theKatyayana Sulba Sutra, which presented muchgeometry, including the generalPythagorean theorem and a computation of thesquare root of 2 correct to five decimal places.
AlthoughJainism as a religion and philosophy predates its most famous exponent,Mahavira (6th century BCE), most Jain texts on mathematical topics were composed after the 6th century BCE.Jain mathematicians are important historically as crucial links between the mathematics of the Vedic period and that of the "classical period."
A significant historical contribution of Jain mathematicians lay in their freeing Indian mathematics from its religious and ritualistic constraints. In particular, their fascination with the enumeration of very large numbers andinfinities led them to classify numbers into three classes: enumerable, innumerable andinfinite. Not content with a simple notion of infinity, their texts define five different types of infinity: the infinite in one direction, the infinite in two directions, the infinite in area, the infinite everywhere, and the infinite perpetually. In addition, Jain mathematicians devised notations for simple powers (and exponents) of numbers like squares and cubes, which enabled them to define simplealgebraic equations (bījagaṇita samīkaraṇa). Jain mathematicians were apparently also the first to use the wordshunya (literallyvoid inSanskrit) to refer to zero. This word is the ultimateetymological origin of the English word "zero", as it wascalqued into Arabic asṣifr and then subsequently borrowed intoMedieval Latin aszephirum, finally arriving at English after passing through one or moreRomance languages (cf. Frenchzéro, Italianzero).[40]
In addition toSurya Prajnapti, important Jain works on mathematics included theSthānāṅga Sūtra (c. 300 BCE – 200 CE); theAnuyogadwara Sutra (c. 200 BCE – 100 CE), which includes the earliest known description offactorials in Indian mathematics;[41] and theṢaṭkhaṅḍāgama (c. 2nd century CE). Important Jain mathematicians includedBhadrabahu (d. 298 BCE), the author of two astronomical works, theBhadrabahavi-Samhita and a commentary on theSurya Prajinapti; Yativrisham Acharya (c. 176 BCE), who authored a mathematical text calledTiloyapannati; andUmasvati (c. 150 BCE), who, although better known for his influential writings on Jain philosophy andmetaphysics, composed a mathematical work called theTattvārtha Sūtra.
Mathematicians of ancient and early medieval India were almost allSanskritpandits (paṇḍita "learned man"),[42] who were trained in Sanskrit language and literature, and possessed "a common stock of knowledge in grammar (vyākaraṇa),exegesis (mīmāṃsā) and logic (nyāya)."[42] Memorisation of "what is heard" (śruti in Sanskrit) through recitation played a major role in the transmission of sacred texts in ancient India. Memorisation and recitation was also used to transmit philosophical and literary works, as well as treatises on ritual and grammar. Modern scholars of ancient India have noted the "truly remarkable achievements of the Indian pandits who have preserved enormously bulky texts orally for millennia."[43]
Prodigious energy was expended by ancient Indian culture in ensuring that these texts were transmitted from generation to generation with inordinate fidelity.[44] For example, memorisation of the sacredVedas included up to eleven forms of recitation of the same text. The texts were subsequently "proof-read" by comparing the different recited versions. Forms of recitation included thejaṭā-pāṭha (literally "mesh recitation") in which every two adjacent words in the text were first recited in their original order, then repeated in the reverse order, and finally repeated in the original order.[45] The recitation thus proceeded as:
In another form of recitation,dhvaja-pāṭha[45] (literally "flag recitation") a sequence ofN words were recited (and memorised) by pairing the first two and last two words and then proceeding as:
The most complex form of recitation,ghana-pāṭha (literally "dense recitation"), according to Filliozat,[45] took the form:
That these methods have been effective is testified to by the preservation of the most ancient Indian religious text, theṚgveda (c. 1500 BCE), as a single text, without any variant readings.[45] Similar methods were used for memorising mathematical texts, whose transmission remained exclusively oral until the end of theVedic period (c. 500 BCE).
Mathematical activity in ancient India began as a part of a "methodological reflexion" on the sacredVedas, which took the form of works calledVedāṇgas, or, "Ancillaries of the Veda" (7th–4th century BCE).[46] The need to conserve the sound of sacred text by use ofśikṣā (phonetics) andchhandas (metrics); to conserve its meaning by use ofvyākaraṇa (grammar) andnirukta (etymology); and to correctly perform the rites at the correct time by the use ofkalpa (ritual) andjyotiṣa (astrology), gave rise to the six disciplines of theVedāṇgas.[46] Mathematics arose as a part of the last two disciplines, ritual and astronomy (which also included astrology).Since theVedāṇgas immediately preceded the use of writing in ancient India, they formed the last of the exclusively oral literature. They were expressed in a highly compressed mnemonic form, thesūtra (literally, "thread"):
The knowers of thesūtra know it as having few phonemes, being devoid of ambiguity, containing the essence, facing everything, being without pause and unobjectionable.[46]
Extreme brevity was achieved through multiple means, which included usingellipsis "beyond the tolerance of natural language",[46] using technical names instead of longer descriptive names, abridging lists by only mentioning the first and last entries, and using markers and variables.[46] Thesūtras create the impression that communication through the text was "only a part of the whole instruction. The rest of the instruction must have been transmitted by the so-calledGuru-shishya parampara, 'uninterrupted succession from teacher (guru) to the student (śisya),' and it was not open to the general public" and perhaps even kept secret.[47] The brevity achieved in asūtra is demonstrated in the following example from the BaudhāyanaŚulba Sūtra (700 BCE).
The domestic fire-altar in theVedic period was required by ritual to have a square base and be constituted of five layers of bricks with 21 bricks in each layer. One method of constructing the altar was to divide one side of the square into three equal parts using a cord or rope, to next divide the transverse (or perpendicular) side into seven equal parts, and thereby sub-divide the square into 21 congruent rectangles. The bricks were then designed to be of the shape of the constituent rectangle and the layer was created. To form the next layer, the same formula was used, but the bricks were arranged transversely.[48] The process was then repeated three more times (with alternating directions) in order to complete the construction. In the BaudhāyanaŚulba Sūtra, this procedure is described in the following words:
II.64. After dividing the quadri-lateral in seven, one divides the transverse [cord] in three.
II.65. In another layer one places the [bricks] North-pointing.[48]
According to Filliozat,[49] the officiant constructing the altar has only a few tools and materials at his disposal: a cord (Sanskrit,rajju, f.), two pegs (Sanskrit,śanku, m.), and clay to make the bricks (Sanskrit,iṣṭakā, f.). Concision is achieved in thesūtra, by not explicitly mentioning what the adjective "transverse" qualifies; however, from the feminine form of the (Sanskrit) adjective used, it is easily inferred to qualify "cord." Similarly, in the second stanza, "bricks" are not explicitly mentioned, but inferred again by the feminine plural form of "North-pointing." Finally, the first stanza, never explicitly says that the first layer of bricks are oriented in the east–west direction, but that too is implied by the explicit mention of "North-pointing" in thesecond stanza; for, if the orientation was meant to be the same in the two layers, it would either not be mentioned at all or be only mentioned in the first stanza. All these inferences are made by the officiant as he recalls the formula from his memory.[48]
With the increasing complexity of mathematics and other exact sciences, both writing and computation were required. Consequently, many mathematical works began to be written down in manuscripts that were then copied and re-copied from generation to generation.
India today is estimated to have about thirty million manuscripts, the largest body of handwritten reading material anywhere in the world. The literate culture of Indian science goes back to at least the fifth century B.C. ... as is shown by the elements of Mesopotamian omen literature and astronomy that entered India at that time and (were) definitely not ... preserved orally.[50]
The earliest mathematical prose commentary was that on the work,Āryabhaṭīya (written 499 CE), a work on astronomy and mathematics. The mathematical portion of theĀryabhaṭīya was composed of 33sūtras (in verse form) consisting of mathematical statements or rules, but without any proofs.[51] However, according to Hayashi,[52] "this does not necessarily mean that their authors did not prove them. It was probably a matter of style of exposition." From the time ofBhaskara I (600 CE onwards), prose commentaries increasingly began to include some derivations (upapatti). Bhaskara I's commentary on theĀryabhaṭīya, had the following structure:[51]
Typically, for any mathematical topic, students in ancient India first memorised thesūtras, which, as explained earlier, were "deliberately inadequate"[50] in explanatory details (in order to pithily convey the bare-bone mathematical rules). The students then worked through the topics of the prose commentary by writing (and drawing diagrams) on chalk- and dust-boards (i.e. boards covered with dust). The latter activity, a staple of mathematical work, was to later prompt mathematician-astronomer,Brahmagupta (fl. 7th century CE), to characterise astronomical computations as "dust work" (Sanskrit:dhulikarman).[53]
It is well known that the decimal place-value systemin use today was first recorded in India, then transmitted to the Islamic world, and eventually to Europe.[54] The Syrian bishopSeverus Sebokht wrote in the mid-7th century CE about the "nine signs" of the Indians for expressing numbers.[54] However, how, when, and where the first decimal place value system was invented is not so clear.[55]
The earliest extantscript used in India was theKharoṣṭhī script used in theGandhara culture of the north-west. It is thought to be ofAramaic origin and it was in use from the 4th century BCE to the 4th century CE. Almost contemporaneously, another script, theBrāhmī script, appeared on much of the sub-continent, and would later become the foundation of many scripts of South Asia and South-east Asia. Both scripts had numeral symbols and numeral systems, which were initiallynot based on a place-value system.[56]
The earliest surviving evidence of decimal place value numerals in India and southeast Asia is from the middle of the first millennium CE.[57] A copper plate from Gujarat, India mentions the date 595 CE, written in a decimal place value notation, although there is some doubt as to the authenticity of the plate.[57] Decimal numerals recording the years 683 CE have also been found in stone inscriptions in Indonesia and Cambodia, where Indian cultural influence was substantial.[57]
There are older textual sources, although the extant manuscript copies of these texts are from much later dates.[58] Probably the earliest such source is the work of the Buddhist philosopher Vasumitra dated likely to the 1st century CE.[58] Discussing the counting pits of merchants, Vasumitra remarks, "When [the same] clay counting-piece is in the place of units, it is denoted as one, when in hundreds, one hundred."[58] Although such references seem to imply that his readers had knowledge of a decimal place value representation, the "brevity of their allusions and the ambiguity of their dates, however, do not solidly establish the chronology of the development of this concept."[58]
A third decimal representation was employed in a verse composition technique, later labelledBhuta-sankhya (literally, "object numbers") used by early Sanskrit authors of technical books.[59] Since many early technical works were composed in verse, numbers were often represented by objects in the natural or religious world that correspondence to them; this allowed a many-to-one correspondence for each number and made verse composition easier.[59] According to Plofker,[60] the number 4, for example, could be represented by the word "Veda" (since there were four of these religious texts), the number 32 by the word "teeth" (since a full set consists of 32), and the number 1 by "moon" (since there is only one moon).[59] So, Veda/teeth/moon would correspond to the decimal numeral 1324, as the convention for numbers was to enumerate their digits from right to left.[59] The earliest reference employing object numbers is a c. 269 CE Sanskrit text,Yavanajātaka (literally "Greek horoscopy") of Sphujidhvaja, a versification of an earlier (c. 150 CE) Indian prose adaptation of a lost work of Hellenistic astrology.[61] Such use seems to make the case that by the mid-3rd century CE, the decimal place value system was familiar, at least to readers of astronomical and astrological texts in India.[59]
It has been hypothesized that the Indian decimal place value system was based on the symbols used on Chinese counting boards from as early as the middle of the first millennium BCE.[62] According to Plofker,[60]
These counting boards, like the Indian counting pits, ..., had a decimal place value structure ... Indians may well have learned of these decimal place value "rod numerals" from Chinese Buddhist pilgrims or other travelers, or they may have developed the concept independently from their earlier non-place-value system; no documentary evidence survives to confirm either conclusion."[62]
The oldest extant mathematical manuscript in India is theBakhshali Manuscript, a birch bark manuscript written in "Buddhist hybrid Sanskrit"[12] in theŚāradā script, which was used in the northwestern region of the Indian subcontinent between the 8th and 12th centuries CE.[63] The manuscript was discovered in 1881 by a farmer while digging in a stone enclosure in the village of Bakhshali, nearPeshawar (then inBritish India and now inPakistan). Of unknown authorship and now preserved in theBodleian Library in theUniversity of Oxford, the manuscript has been dated recently as 224–383 CE.[64]
The surviving manuscript has seventy leaves, some of which are in fragments. Its mathematical content consists of rules and examples, written in verse, together with prose commentaries, which include solutions to the examples.[63] The topics treated include arithmetic (fractions, square roots, profit and loss, simple interest, therule of three, andregula falsi) and algebra (simultaneous linear equations andquadratic equations), and arithmetic progressions. In addition, there is a handful of geometric problems (including problems about volumes of irregular solids). The Bakhshali manuscript also "employs a decimal place value system with a dot for zero."[63] Many of its problems are of a category known as 'equalisation problems' that lead to systems of linear equations. One example from Fragment III-5-3v is the following:
One merchant has sevenasava horses, a second has ninehaya horses, and a third has ten camels. They are equally well off in the value of their animals if each gives two animals, one to each of the others. Find the price of each animal and the total value for the animals possessed by each merchant.[65]
The prose commentary accompanying the example solves the problem by converting it to three (under-determined) equations in four unknowns and assuming that the prices are all integers.[65]
In 2017, three samples from the manuscript were shown byradiocarbon dating to come from three different centuries: from 224 to 383 CE, 680–779 CE, and 885–993 CE. It is not known how fragments from different centuries came to be packaged together.[66][67][68]
This period is often known as the golden age of Indian Mathematics. This period saw mathematicians such asAryabhata,Varahamihira,Brahmagupta,Bhaskara I,Mahavira,Bhaskara II,Madhava of Sangamagrama andNilakantha Somayaji give broader and clearer shape to many branches of mathematics. Their contributions would spread to Asia, the Middle East, and eventually to Europe. Unlike Vedic mathematics, their works included both astronomical and mathematical contributions. In fact, mathematics of that period was included in the 'astral science' (jyotiḥśāstra) and consisted of three sub-disciplines: mathematical sciences (gaṇita ortantra), horoscope astrology (horā orjātaka) and divination (saṃhitā).[53] This tripartite division is seen in Varāhamihira's 6th century compilation—Pancasiddhantika[69] (literallypanca, "five",siddhānta, "conclusion of deliberation", dated 575 CE)—of five earlier works,Surya Siddhanta,Romaka Siddhanta,Paulisa Siddhanta,Vasishtha Siddhanta andPaitamaha Siddhanta, which were adaptations of still earlier works of Mesopotamian, Greek, Egyptian, Roman and Indian astronomy. As explained earlier, the main texts were composed in Sanskrit verse, and were followed by prose commentaries.[53]
Though its authorship is unknown, theSurya Siddhanta (c. 400) contains the roots of moderntrigonometry.[citation needed] Because it contains many words of foreign origin, some authors consider that it was written under the influence ofMesopotamia and Greece.[70][better source needed]
This ancient text uses the following as trigonometric functions for the first time:[citation needed]
Later Indian mathematicians such as Aryabhata made references to this text, while laterArabic andLatin translations were very influential in Europe and the Middle East.
This Chhedi calendar (594) contains an early use of the modernplace-valueHindu–Arabic numeral system now used universally.
Aryabhata (476–550) wrote theAryabhatiya. He described the important fundamental principles of mathematics in 332shlokas. The treatise contained:
Aryabhata also wrote theArya Siddhanta, which is now lost. Aryabhata's contributions include:
Trigonometry:
(See also :Aryabhata's sine table)
Arithmetic:
Algebra:
Mathematical astronomy:
Varahamihira (505–587) produced thePancha Siddhanta (The Five Astronomical Canons). He made important contributions to trigonometry, including sine and cosine tables to 4 decimal places of accuracy and the following formulas relatingsine andcosine functions:
In the 7th century, two separate fields,arithmetic (which includedmeasurement) andalgebra, began to emerge in Indian mathematics. The two fields would later be calledpāṭī-gaṇita (literally "mathematics of algorithms") andbīja-gaṇita (lit. "mathematics of seeds", with "seeds"—like the seeds of plants—representing unknowns with the potential to generate, in this case, the solutions of equations).[72]Brahmagupta, in his astronomical workBrāhma Sphuṭa Siddhānta (628 CE), included two chapters (12 and 18) devoted to these fields. Chapter 12, containing 66 Sanskrit verses, was divided into two sections: "basic operations" (including cube roots, fractions, ratio and proportion, and barter) and "practical mathematics" (including mixture, mathematical series, plane figures, stacking bricks, sawing of timber, and piling of grain).[73] In the latter section, he stated his famous theorem on the diagonals of acyclic quadrilateral:[73]
Brahmagupta's theorem: If a cyclic quadrilateral has diagonals that areperpendicular to each other, then the perpendicular line drawn from the point of intersection of the diagonals to any side of the quadrilateral always bisects the opposite side.
Chapter 12 also included a formula for the area of a cyclic quadrilateral (a generalisation ofHeron's formula), as well as a complete description ofrational triangles (i.e. triangles with rational sides and rational areas).
Brahmagupta's formula: The area,A, of a cyclic quadrilateral with sides of lengthsa,b,c,d, respectively, is given by
wheres, thesemiperimeter, given by
Brahmagupta's Theorem on rational triangles: A triangle with rational sides and rational area is of the form:
for some rational numbers and.[74]
Chapter 18 contained 103 Sanskrit verses which began with rules for arithmetical operations involving zero and negative numbers[73] and is considered the first systematic treatment of the subject. The rules (which included and) were all correct, with one exception:.[73] Later in the chapter, he gave the first explicit (although still not completely general) solution of thequadratic equation:
To the absolute number multiplied by four times the [coefficient of the] square, add the square of the [coefficient of the] middle term; the square root of the same, less the [coefficient of the] middle term, being divided by twice the [coefficient of the] square is the value.[75]
This is equivalent to:
Also in chapter 18, Brahmagupta was able to make progress in finding (integral) solutions ofPell's equation,[76]
where is a nonsquare integer. He did this by discovering the following identity:[76]
Brahmagupta's Identity:which was a generalisation of an earlier identity ofDiophantus:[76] Brahmagupta used his identity to prove the following lemma:[76]
Lemma (Brahmagupta): If is a solution of and, is a solution of, then:
He then used this lemma to both generate infinitely many (integral) solutions of Pell's equation, given one solution, and state the following theorem:
Theorem (Brahmagupta): If the equation has an integer solution for any one of then Pell's equation:
also has an integer solution.[77]
Brahmagupta did not actually prove the theorem, but rather worked out examples using his method. The first example he presented was:[76]
Example (Brahmagupta): Find integers such that:
In his commentary, Brahmagupta added, "a person solving this problem within a year is a mathematician."[76] The solution he provided was:
Bhaskara I (c. 600–680) expanded the work of Aryabhata in his books titledMahabhaskariya,Aryabhatiya-bhashya andLaghu-bhaskariya. He produced:
Virasena (8th century) was a Jain mathematician in the court ofRashtrakuta KingAmoghavarsha ofManyakheta, Karnataka. He wrote theDhavala, a commentary on Jain mathematics, which:
Virasena also gave:
It is thought that much of the mathematical material in theDhavala can attributed to previous writers, especially Kundakunda, Shamakunda, Tumbulura, Samantabhadra and Bappadeva and date who wrote between 200 and 600 CE.[79]
Mahavira Acharya (c. 800–870) fromKarnataka, the last of the notable Jain mathematicians, lived in the 9th century and was patronised by the Rashtrakuta king Amoghavarsha. He wrote a book titledGanit Saar Sangraha on numerical mathematics, and also wrote treatises about a wide range of mathematical topics. These include the mathematics of:
Mahavira also:
Shridhara (c. 870–930), who lived inBengal, wrote the books titledNav Shatika,Tri Shatika andPati Ganita. He gave:
ThePati Ganita is a work on arithmetic andmeasurement. It deals with various operations, including:
Aryabhata's equations were elaborated in the 10th century by Manjula (alsoMunjala), who realised that the expression[80]
could be approximately expressed as
This was elaborated by his later successor Bhaskara ii thereby finding the derivative of sine.[80]
Aryabhata II (c. 920–1000) wrote a commentary on Shridhara, and an astronomical treatiseMaha-Siddhanta. The Maha-Siddhanta has 18 chapters, and discusses:
Shripati Mishra (1019–1066) wrote the booksSiddhanta Shekhara, a major work on astronomy in 19 chapters, andGanit Tilaka, an incompletearithmetical treatise in 125 verses based on a work by Shridhara. He worked mainly on:
He was also the author ofDhikotidakarana, a work of twenty verses on:
TheDhruvamanasa is a work of 105 verses on:
Nemichandra Siddhanta Chakravati (c. 1100) authored a mathematical treatise titledGome-mat Saar.
Bhāskara II (1114–1185) was a mathematician-astronomer who wrote a number of important treatises, namely theSiddhanta Shiromani,Lilavati,Bijaganita,Gola Addhaya,Griha Ganitam andKaran Kautoohal. A number of his contributions were later transmitted to the Middle East and Europe. His contributions include:
Arithmetic:
Algebra:
Geometry:
Calculus:
Trigonometry:
The Navya-Nyāya or Neo-Logical darśana (school) of Indian philosophy was founded in the 13th century by the philosopherGangesha Upadhyaya ofMithila.[82] It was a development of the classical Nyāya darśana. Other influences on Navya-Nyāya were the work of earlier philosophersVācaspati Miśra (900–980 CE) andUdayana (late 10th century).
Gangeśa's bookTattvacintāmaṇi ("Thought-Jewel of Reality") was written partly in response to Śrīharśa's Khandanakhandakhādya, a defence ofAdvaita Vedānta, which had offered a set of thorough criticisms of Nyāya theories of thought and language.[83] Navya-Nyāya developed a sophisticated language and conceptual scheme that allowed it to raise, analyze, and solve problems in logic and epistemology. It involves naming each object to be analyzed, identifying a distinguishing characteristic for the named object, and verifying the appropriateness of the defining characteristic usingpramanas.[84]
TheKerala school of astronomy and mathematics was founded byMadhava of Sangamagrama in Kerala,South India and included among its members:Parameshvara,Neelakanta Somayaji,Jyeshtadeva,Achyuta Pisharati,Melpathur Narayana Bhattathiri and Achyuta Panikkar. It flourished between the 14th and 16th centuries and the original discoveries of the school seems to have ended with Narayana Bhattathiri (1559–1632). In attempting to solve astronomical problems, the Kerala school astronomersindependently created a number of important mathematics concepts. The most important results, series expansion fortrigonometric functions, were given inSanskrit verse in a book by Neelakanta calledTantrasangraha and a commentary on this work calledTantrasangraha-vakhya of unknown authorship. The theorems were stated without proof, but proofs for the series forsine,cosine, and inversetangent were provided a century later in the workYuktibhāṣā (c.1500–c.1610), written inMalayalam, byJyesthadeva.[85]
Their discovery of these three important series expansions ofcalculus—several centuries before calculus was developed in Europe byIsaac Newton andGottfried Leibniz—was an achievement. However, the Kerala School did not inventcalculus,[86] because, while they were able to developTaylor series expansions for the importanttrigonometric functions, they developed neither a theory ofdifferentiation orintegration, nor thefundamental theorem of calculus.[71] The results obtained by the Kerala school include:
The works of the Kerala school were first written up for the Western world by EnglishmanC.M. Whish in 1835. According to Whish, the Kerala mathematicians had "laid the foundation for a complete system of fluxions" and these works abounded "with fluxional forms and series to be found in no work of foreign countries."[88]
However, Whish's results were almost completely neglected, until over a century later, when the discoveries of the Kerala school were investigated again by C. Rajagopal and his associates. Their work includes commentaries on the proofs of the arctan series inYuktibhāṣā given in two papers,[89][90] a commentary on theYuktibhāṣā's proof of the sine and cosine series[91] and two papers that provide the Sanskrit verses of theTantrasangrahavakhya for the series for arctan, sin, and cosine (with English translation and commentary).[92][93]
Parameshvara (c. 1370–1460) wrote commentaries on the works ofBhaskara I,Aryabhata and Bhaskara II. HisLilavati Bhasya, a commentary on Bhaskara II'sLilavati, contains one of his important discoveries: a version of themean value theorem.Nilakantha Somayaji (1444–1544) composed theTantra Samgraha (which 'spawned' a later anonymous commentaryTantrasangraha-vyakhya and a further commentary by the nameYuktidipaika, written in 1501). He elaborated and extended the contributions of Madhava.
Citrabhanu (c. 1530) was a 16th-century mathematician from Kerala who gave integer solutions to 21 types of systems of twosimultaneous algebraic equations in two unknowns. These types are all the possible pairs of equations of the following seven forms:
For each case, Citrabhanu gave an explanation and justification of his rule as well as an example. Some of his explanations are algebraic, while others are geometric.Jyesthadeva (c. 1500–1575) was another member of the Kerala School. His key work was theYukti-bhāṣā (written in Malayalam, a regional language of Kerala). Jyesthadeva presented proofs of most mathematical theorems and infinite series earlier discovered by Madhava and other Kerala School mathematicians.
Narayana Pandit was a 14th century mathematician who composed two important mathematical works, an arithmetical treatise,Ganita Kaumudi, and an algebraic treatise,Bijganita Vatamsa.Ganita Kaumudi is one of the most revolutionary works in the field of combinatorics with developing a method forsystematic generation of all permutations of a given sequence.In hisGanita Kaumudi Narayana proposed the following problem on a herd of cows and calves:
A cow produces one calf every year. Beginning in its fourth year, each calf produces one calf at the beginning of each year. How many cows and calves are there altogether after 20 years?
Translated into the modern mathematical language ofrecurrence sequences:
with initial values
The first few terms are 1, 1, 1, 2, 3, 4, 6, 9, 13, 19, 28, 41, 60, 88,... (sequenceA000930 in theOEIS).The limit ratio between consecutive terms is thesupergolden ratio.. Narayana is also thought to be the author of an elaborate commentary ofBhaskara II'sLilavati, titledGanita Kaumudia(orKarma-Paddhati).[94]
It has been suggested that Indian contributions to mathematics have not been given due acknowledgement in modern history and that many discoveries and inventions byIndian mathematicians are presently culturally attributed to theirWestern counterparts, as a result ofEurocentrism. According to G. G. Joseph's take on "Ethnomathematics":
[Their work] takes on board some of the objections raised about the classical Eurocentric trajectory. The awareness [of Indian and Arabic mathematics] is all too likely to be tempered with dismissive rejections of their importance compared to Greek mathematics. The contributions from other civilisations – most notably China and India, are perceived either as borrowers from Greek sources or having made only minor contributions to mainstream mathematical development. An openness to more recent research findings, especially in the case of Indian and Chinese mathematics, is sadly missing"[95]
Historian of mathematicsFlorian Cajori wrote that he and others "suspect thatDiophantus got his first glimpse of algebraic knowledge from India".[96] He also wrote that "it is certain that portions of Hindu mathematics are of Greek origin".[97]
More recently, as discussed in the above section, the infinite series ofcalculus for trigonometric functions (rediscovered by Gregory, Taylor, and Maclaurin in the late 17th century) were described in India, by mathematicians of theKerala school, some two centuries earlier. Some scholars have recently suggested that knowledge of these results might have been transmitted to Europe through the trade route fromKerala by traders andJesuit missionaries.[98] Kerala was in continuous contact with China andArabia, and, from around 1500, with Europe. The fact that the communication routes existed and the chronology is suitable certainly make such transmission a possibility. However, no evidence of transmission has been found.[98] According toDavid Bressoud, "there is no evidence that the Indian work of series was known beyond India, or even outside of Kerala, until the nineteenth century".[86][99]
Both Arab and Indian scholars made discoveries before the 17th century that are now considered a part of calculus.[71] However, they did not (asNewton andLeibniz did) "combine many differing ideas under the two unifying themes of thederivative and theintegral, show the connection between the two, and turn calculus into the great problem-solving tool we have today".[71] The intellectual careers of both Newton and Leibniz are well-documented and there is no indication of their work not being their own;[71] however, it is not known with certainty whether the immediatepredecessors of Newton and Leibniz, "including, in particular, Fermat and Roberval, [may have] learned of some of the ideas of the Islamic and Indian mathematicians through sources we are not now aware."[71] This is an area of current research, especially in the manuscript collections of Spain andMaghreb, and is being pursued, among other places, at theCNRS.[71]
figure which stands for naught in the Arabic notation," also "the absence of all quantity considered as quantity",c. 1600, from French zéro or directly from Italian zero, from Medieval Latin zephirum, from Arabic sifr "cipher", translation of Sanskrit sunya-m "empty place, desert, naught
French zéro (1515 in Hatzfeld & Darmesteter) or its source Italian zero, for *zefiro, < Arabic çifr
The wordSiddhanta meansthat which is proved or established. TheSulva Sutras are of Hindu origin, but theSiddhantas contain so many words of foreign origin that they undoubtedly have roots inMesopotamia and Greece.
{{cite book}}: CS1 maint: publisher location (link){{cite book}}:ISBN / Date incompatibility (help){{cite book}}:ISBN / Date incompatibility (help)In algebra, there was probably a mutual giving and receiving [between Greece and India]. We suspect that Diophantus got his first glimpse of algebraic knowledge from India
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