上代码: subplot(1,1,1); b = 1; a = [1, -0.8]; n = [0:100]; x = cos(0.05*pi*n); y = filter(b,a,x); figure('NumberTitle', 'off', 'Name', 'Input and Output sequence'); set(gcf,'Color','white'); subplot(2,1,1); stem(n,x); title('Input sequence'); xlabel('n'…