This is a summary of differentiation rules, that is, rules for computing the derivative of a function in calculus.

Elementary rules of differentiation

Unless otherwise stated, all functions are functions of real numbers (R) that return real values; although more generally, the formulae below apply wherever they are well defined[1][2]—including complex numbers (C).[3]

Differentiation is linear

Main article: Linearity of differentiation

For any functions f and g and any real numbers a and b the derivative of the function h(x) = af(x) + bg(x) with respect to x is

In Leibniz's notation this is written as:

Special cases include:

The product rule

Main article: Product rule

For the functions f and g, the derivative of the function h(x) = f(x) g(x) with respect to x is

In Leibniz's notation this is written

The chain rule

Main article: Chain rule

The derivative of the function of a function h(x) = f(g(x)) with respect to x is

In Leibniz's notation this is written as:

However, by relaxing the interpretation of h as a function, this is often simply written

The inverse function rule

Main article: inverse functions and differentiation

If the function f has an inverse function g, meaning that g(f(x)) = x and f(g(y)) = y, then

In Leibniz notation, this is written as

Power laws, polynomials, quotients, and reciprocals

The polynomial or elementary power rule

Main article: Power rule

If , for any integer n then

Special cases include:

Combining this rule with the linearity of the derivative and the addition rule permits the computation of the derivative of any polynomial.

The reciprocal rule

Main article: Reciprocal rule

The derivative of h(x) = 1/f(x) for any (nonvanishing) function f is:

In Leibniz's notation, this is written

The reciprocal rule can be derived from the chain rule and the power rule.

The quotient rule

Main article: Quotient rule

If f and g are functions, then:

wherever g is nonzero.

This can be derived from reciprocal rule and the product rule. Conversely (using the constant rule) the reciprocal rule may be derived from the special case f(x) = 1.

Generalized power rule

Main article: Power rule

The elementary power rule generalizes considerably. The most general power rule is the functional power rule: for any functions f and g,

wherever both sides are well defined.

Special cases:

Derivatives of exponential and logarithmic functions

note that the equation above is true for all c, but the derivative for c < 0 yields a complex number.

the equation above is also true for all c but yields a complex number if c<0.

Logarithmic derivatives

The logarithmic derivative is another way of stating the rule for differentiating the logarithm of a function (using the chain rule):

wherever f is positive.

Derivatives of trigonometric functions

Main article: Differentiation of trigonometric functions

It is common to additionally define an inverse tangent function with two arguments, . Its value lies in the range and reflects the quadrant of the point . For the first and fourth quadrant (i.e. ) one has . Its partial derivatives are

, and

Derivatives of hyperbolic functions

Derivatives of special functions

Gamma function

Riemann Zeta function

Derivatives of integrals

Main article: Differentiation under the integral sign

Suppose that it is required to differentiate with respect to x the function

where the functions and are both continuous in both and in some region of the plane, including , and the functions and are both continuous and both have continuous derivatives for . Then for :

This formula is the general form of the Leibniz integral rule and can be derived using the fundamental theorem of calculus.

Derivatives to nth order

Some rules exist for computing the nth derivative of functions, where n is a positive integer. These include:

Faà di Bruno's formula

Main article: Faà di Bruno's formula

If f and g are n times differentiable, then

where and the set consists of all non-negative integer solutions of the Diophantine equation .

General Leibniz rule

Main article: General Leibniz rule

If f and g are n times differentiable, then

See also

References

  1. ^ Calculus (5th edition), F. Ayres, E. Mendelson, Schuam's Outline Series, 2009, ISBN 978-0-07-150861-2.
  2. ^ Advanced Calculus (3rd edition), R. Wrede, M.R. Spiegel, Schuam's Outline Series, 2010, ISBN 978-0-07-162366-7.
  3. ^ Complex Variables, M.R. Speigel, S. Lipschutz, J.J. Schiller, D. Spellman, Schaum's Outlines Series, McGraw Hill (USA), 2009, ISBN 978-0-07-161569-3

Sources and further reading

These rules are given in many books, both on elementary and advanced calculus, in pure and applied mathematics. Those in this article (in addition to the above references) can be found in: