Inverse function

In mathematics, if a function f(x)=y is injective, exactly one function g(y) will exist such that g(y)=x, otherwise no such function will exist.

The function g(y) is called the inverse function of f(x) because it "reverses" f(x); that is to say g(f(x))=x.

See also

• Function (mathematics)
• Injective function
• Inverse function theorem, gives sufficient conditions for a function to be invertible in a neighborhood of a point in its domain and gives a formula for the derivative of the inverse function
• Inverse functions and differentiation
• Inverse relation
• Lagrange inversion theorem, gives the Taylor series expansion of the inverse function of an analytic function

External links

• Inverse function @ Wikipedia