Having trouble using the function command.

The interest you get at the end of n years, at a flat annual rate of r% depends on how the interest is compounded. If the interest is added to your account k times a year, and the principal amount you invested is Xo, then at the end of n years you would have X-X,[+-l amount of money in your account. Write a function to compute the interest (X-Xo) on your account for a given Xo, n, r, and k. Use the function to find the difference between the interest paid on $1000 at the rate of 6% a year at the end of 5 years if the interest is compounded (i) quarterly (k-4 and (ii daily (k-365)