Second derivative rule for inverse function

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This article is about a differentiation rule, i.e., a rule for differentiating a function expressed in terms of other functions whose derivatives are known.
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Statement

Simple version at a specific point

Suppose f is a one-one function and a is a point in the domain of f such that f is twice differentiable at a and f(a)0 where f denotes the derivative of f. Suppose b=f(a).

Then, we have the following formula for the second derivative of the inverse function f1:

(f1)(b)=f(a)(f(a))3

Simple version at a generic point

Suppose f is a one-one function. Then, we have the following formula:

(f1)(x)=f(f1(x))(f(f1(x)))3

where the formula is applicable for all x in the range of f for which f is twice differentiable at f1(x) and the first derivative of f at f1(x) is nonzero.