Write a function public static double binomial(int n, int k, double p)
to compute the probability of obtaining exactly k heads in n biased coin flips (heads with probability p) using the formulaTo stave off overflow, compute x = ln f (n, k, p) and then return ex. In main(), take n and p from the command line and check that the sum over all values of k between 0 and n is (approximately) 1. Also, compare every value computed with the normal approximation 

f(n, k, p) pk(1-p)"-kn!/(k!(n-k)!)