两信号加减或相乘（Matlab）

两信号加减或相乘

f1(x)=sin(x),f2(x)=sin(8x)
f1(x)+f2(x)=sin(x)+sin(8x)
f1(x)*f2(x)=sin(x)*sin(8x)

x=[-10:0.01:10];
y1=sin(x);
y2=sin(8*x);
y3=y1+y2;
y4=y1.*y2;

subplot(2,2,1)
plot(x,y1,'r');

subplot(2,2,2)
plot(x,y2,'b');

subplot(2,2,3)
plot(x,y3,'c');

subplot(2,2,4)
plot(x,y4,'m');