Math.h and cmath in c++

Question

In a lot of challenges, one is used and one isn’t
What is the difference between each one and what functions do you use each for?

Answer 1

The C++ library includes the same definitions as the C language library organized in the same structure of header files, with the following differences:

1 - Each header file has the same name as the C language version but with a "c" prefix and no extension. For example, the C++ equivalent for the C language header file < stdlib.h > is < cstdlib>.

2 - Every element of the library is defined within the std namespace.

http://www.cplusplus.com/reference/clibrary/