Write a function called square_wave that computes the sum
for each of 1001 values of t uniformly spaced from 0 to 4π inclusive.
The input argument is a positive scalar integer n, and the output argument is a row vector of 1001 such sums—one sum for each value of t. You can test your function by calling it with n == 200 or greater and plotting the result, and you will see why the function is called “square_wave”.
