The chain rule in calculus is the formula for the derivative/differentiation of a composition of functions or operations.
Chain rule may also refer to other formulas/equations:
Cyclic chain rule (AKA Euler's chain rule, triple product rule, cyclic relation, reciprocity theorem), relating partial derivatives of three interdependent variables Finding a property of 'X and Y' by combining the same property of 'X' and 'Y given X': Chain rule (probability) (AKA general product rule), for the chance of multiple events all occurring (their intersection) or the joint distribution of random variables Chain rule for Kolmogorov complexity, for the minimum size of a program that produces a certain output, given programs for computing the start and the remainder Chain rule for entropy (information theory), for the Shannon entropy of two consecutive experiments
See also
Reverse chain rule (AKA integration by substitution, u-substitution, change of variables), the related method for evaluating integrals and antiderivatives