The original notation employed byGottfried Leibniz is used throughout mathematics. It is particularly common when the equationy =f(x) is regarded as a functional relationship betweendependent and independent variablesy andx. Leibniz's notation makes this relationship explicit by writing the derivative as:[1]Furthermore, the derivative off atx is therefore written
Higher derivatives are written as:[2]This is a suggestive notational device that comes from formal manipulations of symbols, as in,
The value of the derivative ofy at a pointx =a may be expressed in two ways using Leibniz's notation:
Leibniz's notation allows one to specify the variable for differentiation (in the denominator). This is especially helpful when consideringpartial derivatives. It also makes thechain rule easy to remember and recognize:
Leibniz's notation for differentiation does not require assigning meaning to symbols such asdx ordy (known asdifferentials) on their own, and some authors do not attempt to assign these symbols meaning.[1] Leibniz treated these symbols asinfinitesimals. Later authors have assigned them other meanings, such as infinitesimals innon-standard analysis, orexterior derivatives. Commonly,dx is left undefined or equated with, whiledy is assigned a meaning in terms ofdx, via the equation
which may also be written, e.g.
(seebelow). Such equations give rise to the terminology found in some texts wherein the derivative is referred to as the "differential coefficient" (i.e., thecoefficient ofdx).
Some authors and journals set the differential symbold inroman type instead ofitalic:dx. TheISO/IEC 80000 scientific style guide recommends this style.
A functionf ofx, differentiated once in Lagrange's notation.
One of the most common modern notations for differentiation is named afterJoseph Louis Lagrange, although it was in fact invented byEuler and popularized by the former. In Lagrange's notation, aprime mark denotes a derivative – hence it is sometimes calledprime notation. Iff is a function, then its derivative evaluated atx is written
Higher derivatives are indicated using additional prime marks, as in for thesecond derivative and for thethird derivative. The use of repeated prime marks eventually becomes unwieldy; some authors continue by employingRoman numerals, usually in lower case,[4][5] as in
to denote fourth, fifth, sixth, and higher order derivatives. Other authors use Arabic numerals in parentheses, as in
This notation also makes it possible to describe thenth derivative, wheren is a variable. This is written
Unicode characters related to Lagrange's notation include
U+2032◌′PRIME (derivative)
U+2033◌″DOUBLE PRIME (double derivative)
U+2034◌‴TRIPLE PRIME (third derivative)
U+2057◌⁗QUADRUPLE PRIME (fourth derivative)
When there are two independent variables for a function, the following notation was sometimes used:[6]
The single and double indefinite integrals off with respect tox, in the Lagrange notation.
When taking the antiderivative, Lagrange followed Leibniz's notation:[7]
However, because integration is the inverse operation of differentiation, Lagrange's notation for higher order derivatives extends to integrals as well. Repeated integrals off may be written as
for the first integral (this is easily confused with theinverse function),
Higher derivatives are notated as "powers" ofD (where the superscripts denote iteratedcomposition ofD), as in[6]
for the second derivative,
for the third derivative, and
for thenth derivative.
D-notation leaves implicit the variable with respect to which differentiation is being done. However, this variable can also be made explicit by putting its name as a subscript: iff is a function of a variablex, this is done by writing[6]
for the first derivative,
for the second derivative,
for the third derivative, and
for thenth derivative.
Whenf is a function of several variables, it is common to use "∂", a stylized cursive lower-case d, rather than "D". As above, the subscripts denote the derivatives that are being taken. For example, the second partial derivatives of a function are:[6]
The first and second derivatives ofx, Newton's notation.
Isaac Newton's notation for differentiation (also called thedot notation,fluxions, or sometimes, crudely, theflyspeck notation[12] for differentiation) places a dot over the dependent variable. That is, ify is a function oft, then the derivative ofy with respect tot is
Higher derivatives are represented using multiple dots, as in
The first and second antiderivatives ofx, in one of Newton's notations.
Newton developed many different notations forintegration in hisQuadratura curvarum (1704) andlater works: he wrote a small vertical bar or prime above the dependent variable (y̍ ), a prefixing rectangle (▭y), or the inclosure of the term in a rectangle (y) to denote thefluent or time integral (absement).
To denote multiple integrals, Newton used two small vertical bars or primes (y̎), or a combination of previous symbols▭y̍y̍, to denote the second time integral (absity).
For a functionf of a single independent variablex, we can express the derivative using subscripts of the independent variable:
This type of notation is especially useful for takingpartial derivatives of a function of several variables.
∂f/∂x
A functionf differentiated againstx.
Partial derivatives are generally distinguished from ordinary derivatives by replacing the differential operatord with a "∂" symbol. For example, we can indicate the partial derivative off(x, y, z) with respect tox, but not toy orz in several ways:
What makes this distinction important is that a non-partial derivative such asmay, depending on the context, be interpreted as a rate of change in relative to when all variables are allowed to vary simultaneously, whereas with a partial derivative such as it is explicit that only one variable should vary.
Other notations can be found in various subfields of mathematics, physics, and engineering; see for example theMaxwell relations ofthermodynamics. The symbol is the derivative of the temperatureT with respect to the volumeV while keeping constant the entropy (subscript)S, while is the derivative of the temperature with respect to the volume while keeping constant the pressureP. This becomes necessary in situations where the number of variables exceeds the degrees of freedom, so that one has to choose which other variables are to be kept fixed.
Higher-order partial derivatives with respect to one variable are expressed as
and so on. Mixed partial derivatives can be expressed as
In this last case the variables are written in inverse order between the two notations, explained as follows:
So-calledmulti-index notation is used in situations when the above notation becomes cumbersome or insufficiently expressive. When considering functions on, we define a multi-index to be an ordered list of non-negative integers:. We then define, for, the notation
In this way some results (such as theLeibniz rule) that are tedious to write in other ways can be expressed succinctly -- some examples can be found in thearticle on multi-indices.[20]
The differential operator introduced byWilliam Rowan Hamilton, written∇ and calleddel or nabla, is symbolically defined in the form of a vector,
where the terminologysymbolically reflects that the operator ∇ will also be treated as an ordinary vector.
∇φ
Gradient of the scalar fieldφ.
Gradient: The gradient of the scalar field is a vector, which is symbolically expressed by themultiplication of ∇ and scalar field,
∇∙A
The divergence of the vector fieldA.
Divergence: The divergence of the vector fieldA is a scalar, which is symbolically expressed by thedot product of ∇ and the vectorA,
∇2φ
The Laplacian of the scalar fieldφ.
Laplacian: The Laplacian of the scalar field is a scalar, which is symbolically expressed by the scalar multiplication of ∇2 and the scalar fieldφ,
∇×A
The curl of vector fieldA.
Rotation: The rotation, or, of the vector fieldA is a vector, which is symbolically expressed by thecross product of ∇ and the vectorA,
Many symbolic operations of derivatives can be generalized in a straightforward manner by the gradient operator in Cartesian coordinates. For example, the single-variableproduct rule has a direct analogue in the multiplication of scalar fields by applying the gradient operator, as in
Many other rules from single variable calculus havevector calculus analogues for the gradient, divergence, curl, and Laplacian.
Further notations have been developed for more exotic types of spaces. For calculations inMinkowski space, thed'Alembert operator, also called the d'Alembertian, wave operator, or box operator is represented as, or as when not in conflict with the symbol for the Laplacian.
^Morris, Carla C. (2015-07-28).Fundamentals of calculus. Stark, Robert M., 1930-2017. Hoboken, New Jersey.ISBN9781119015314.OCLC893974565.{{cite book}}: CS1 maint: location missing publisher (link)
^abWeisstein, Eric W. "Differential Operator." FromMathWorld--A Wolfram Web Resource."Differential Operator".Archived from the original on 2016-01-21. Retrieved2016-02-07.
^Weisstein, Eric W. "Repeated Integral." FromMathWorld--A Wolfram Web Resource."Repeated Integral".Archived from the original on 2016-02-01. Retrieved2016-02-07.
1st to 7th,nth and (n+1)th derivatives:Method of Fluxions (Newton, 1736), pp. 313-318 and p. 265 (p. 163 in original MS:"Newton Papers : Fluxions".Archived from the original on 2017-04-06. Retrieved2016-02-05.)
1st to 5th derivatives :A Treatise of Fluxions (Colin MacLaurin, 1742), p. 613
1st to 4th andnth derivatives: Articles "Differential" and "Fluxion",Dictionary of Pure and Mixed Mathematics (Peter Barlow, 1814)
1st to 6th andnth derivatives:The Mathematical Papers of Isaac Newton Vol. 7 1691-1695 (D. T. Whiteside, 1976), pp.88 and 17
1st to 3rd andnth derivatives:A History of Analysis (Hans Niels Jahnke, 2000), pp. 84-85
The dot fornth derivative may be omitted ( )
^Weisstein, Eric W. "Overdot." FromMathWorld--A Wolfram Web Resource."Overdot".Archived from the original on 2015-09-05. Retrieved2016-02-05.
^Weisstein, Eric W. "Double Dot." FromMathWorld--A Wolfram Web Resource."Double Dot".Archived from the original on 2016-03-03. Retrieved2016-02-05.
^Article 580 in Florian Cajori,A History of Mathematical Notations (1929), Dover Publications, Inc. New York.ISBN0-486-67766-4
^"Patterns of Mathematical Thought in the Later Seventeenth Century",Archive for History of Exact Sciences Vol. 1, No. 3 (D. T. Whiteside, 1961), pp. 361-362,378
^S.B. Engelsman has given more strict definitions inFamilies of Curves and the Origins of Partial Differentiation (2000), pp. 223-226
^Newton's notation for integration reproduced from:
1st to 3rd integrals:Method of Fluxions (Newton, 1736), pp. 265-266 (p. 163 in original MS:"Newton Papers : Fluxions".Archived from the original on 2017-04-06. Retrieved2016-02-05.)
4th integrals:The Doctrine of Fluxions (James Hodgson, 1736), pp. 54 and 72
1st to 2nd integrals: Articles 622 and 365 inA History of Mathematical Notations (F .Cajori, 1929)
Thenth integral notation is deducted from thenth derivative. It could be used inMethodus Incrementorum Directa & Inversa (Brook Taylor, 1715)