Any programming language includes many built-in functions that can be used in arithmetic expressions.
To use additional functions, you often have to connect additional libraries.
For example, the most commonly used standard mathematical functions and their writing in C and C ++
abs(i)
absolute value of an integer i
fabs(x)
absolute value of a real числа x
sqrt(x)
Square root x
pow(x,y)
x**y
It must be remembered that the function argument is always written in brackets.
For these functions to work, you need to connect an additional mathematical library.
You can do this by adding a line
#include<math.h>