%q8
wc = 2*pi*25e6

t1 = [0:1e-12:0.1e-6];
s1 = 1.1*cos(wc*t1);

t2 = [0.1e-6:1e-12:1e-6];
s2 = 2*cos(wc*t2);

t3 = [1e-6:1e-12:1.9e-6];
s3 = (3-t3).*cos(wc*t3);

t4 = [1.9e-6: 1e-12 :2e-6];
s4 = 1.1*cos(wc*t4);

t = horzcat(t1,t2,t3,t4);
s = horzcat(s1,s2,s3,s4);

%pot média:
s_mean = mean(s.^2)

plot(t, s.^2)