Exercise p8.11 on page 382

Consider the following algorithm for computing xⁿ for an integer n.
If n<0, xⁿ is 1/x^-n.
If n is positive and even, then xⁿ = (x^n/2)².
If n is positive and odd, then xⁿ = x^n-1 * x.
Implement a static method
double intPower(double x, int n)
that uses this algorithm.
Add it to a class called Numeric.