function circuit()
t=[0:0.01:10];
x=10.*exp(-0.5.*t).*sin(3.*t+2);
y=7.*exp(-0.4.*t).*cos(5.*t-3);
plot(t,x,t,y);
legend('x(t)','y(t)');
title('Problem 15 page 343');
ylabel('x(t) and y(t)');
xlabel('t');