t=0:.1:250;f=.05;x = (square(2*3.14*f*t)+1)/2;subplot(5,1,1);plot(t,x);fc1=500;fc2=1000;c1=s!"(2*3.14*fc1*t);subplot(5,1,2);plot(t,c1);#=c1.*x;subplot(5,1,3);plot(t,#);c2=s!"(2*3.14*fc2*t);subplot(5,1,4);plot(t,c2);for !=1:le"$t%(t)!f(x(!)&0)#1(!)=c2(!).*x(!);else#1(!)=c1(!).*(1'x(!));e"(e"( subplot(5,1,5);plot(t,#1);