An LTI discrete time system has the impulse response h[n] = (−1)ⁿ u[n]. Use the convolution sum to compute the output response y[n],n ≥ 0, when the input is x[n] = u[n] − u[n − 3] and the initial conditions are zero. In particular, find the following values of the out-put y[n],0 ≤ n ≤ 4.