Write a C$++$ program that calculates an absolute number, a power, a square root, rounding up$,$ rounding down, and rounding to the nearest by calling predefined functions. You must include $$cmath$$ to use mathematical functions. $($#include $)$

List of functions

double abs $($double x$)$; $//$ returns the absolute value of x: $(|$x$|)$

double pow $($double b$,$ double e$)$; $//$ returns b raised to the power e: $($b$^$e$)$

double sqrt $($double x$)$; $//$ returns the square root of x: $((2$&x$))$

double round $($double x$)$; $//$ returns the integral value that is nearest to x

double ceil $($double x$)$; $//$ returns x upward

double floor $($double x$)$; $//$ returns x downward

Sample Output: Red colored texts are user inputs. Other texts are the output of the program.

$|-21|=21$

$2^3=8$

A square root of $16=4$

Rounding up $3\mathrm{.}5=4$

Rounding down $3\mathrm{.}5=3$

Rounding $3\mathrm{.}5$ to the nearest integer $=4$