How to find the derivative of a function in C++?

Question

C++ / C#

How to find the derivative of a function in C++?

Answer 1

Derivative in the sense of differentiation? f'(x) in the general case is possible only numerically and approximately. We take a sufficiently small dx and then f'(x)=(f(x+dx)-f(x))/dx. If the function is given analytically, then you can here www.wolframalpha.com/input/?i=d%2Fdx+Si(x)%5E2&lk=3