Write a function called fourier which takes input parameters c and num where c is a Python list of numbers c = [c0,cl,..., CN] and num is a postive integer. The function fourier plots the function f(x) = 2 N + ck os(2kx) k=1 over the interval [0, 1] using num equally spaced points from 0 to 1. (In other words, use np. linspace(0, 1, num) for the x values.) The function also returns the x and y values of the plot in a matrix with 2 columns with x values in the first column and y values in the second. The function np.column_stack may be helpful. (Note that the function is a (partial) I