Use MATLAB to plot the following functions: y_1(t) = [u(t) - u(t - 1)] y_2(t) = [u(t - 1) - u(t - 2)] y_3(t) = [u(t + 1) - u(t - 1)] y_4(t) = u(t + 1) y_5(t) = y_1(t) * y_1(t) y_6 (t) = y_1 (t) * y_2(t) y_7(t) = y_1(t) * y_3(t) y_8(t) = y_1(t) * y_4(t) y_9(t) = y_2(t)* y_3(t) y_10(t) = y_1(t) * y_2(t) * y_3(t)