Python - write math function for Simpson's rule

Make a function defined as: def Simpson(fcn, a, b, npoints = 11):

Purpose: use Simpson's 1/3 rule to estimate the integral of fcn(x), between the limits of a and b.

fcn: the function we want to integrate

a and b: the lower and upper limits of integration

npoints: The number of integration points used in the range a to b (inclusive). Npoints must be an ODD number. If npoints is not ODD, then add 1 to make it odd!

return value: the estimate of the integral

Write and call a main() function that uses your Simpson function to estimate and print the integral of:

x - 3 * cos(x) , with a = 1, b = 3 and npoints = 14

cos(2x)*x³ , with a = 2, b = 3 and npoints = 29