In calculus, the chain rule is formula for computing the derivative of the composition of two or more functions That is, if f and g are functions, then the chain rule expresses the derivative of their composition f ∘ g (the function which maps x to f(g(x)) in terms of the derivatives of f and g and the product of functions as follows: This can be written more explicitly in terms of the variable. Let F = f ∘ g, or equivalently, F(x) = f(g(x)) for all x. Then one can also write 

A chain with rule is called chain rule yaar
Thnx for wt ?
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thnx for tht
:P hmm...   Kk mohtarma
wat do u mean by mohtarma?