How to use Maths functions in C++?

Answer 1

using Math class by including-
#include<math.h>

Use functions like Math.abs(), Math.sqrt(), Math.sin() etc.

Answer 2

Actually, I got confused with programming languages. But you are right that prefix Math. is invalid but <math.h> and <cmath> both have same functions.
reference-
http://www.cplusplus.com/reference/cmath/

Answer 3

palindrome using string function