## illogical plotting and results in delayed function

### Trulien Elmer (view profile)

on 10 Nov 2018
Latest activity Edited by Walter Roberson

### Walter Roberson (view profile)

on 10 Nov 2018
Here is the function im dealing with
clear;
syms x(t) X(w)
f1 = 2;
f2 = 3;
x(t) =cos(2*pi*f1*t)
subplot(2,1,1);
ezplot(x);
subplot(2,1,2);
ezplot(x(t-10));
And here are the results
how is this possible, even though there it is a delayed function?

Walter Roberson

### Walter Roberson (view profile)

on 10 Nov 2018
You expect the plots to be different. What is a specific t value at which you expect the two plots to have a different value, and what value are you expecting there for the two different plots ?
Trulien Elmer

### Trulien Elmer (view profile)

on 10 Nov 2018
im not looking for a huge difference, all im looking for is a delayed cosine function by 10 units for every single time by using ezplot and syms function. isnt that what x(t-10) = cos(t) going to look like?
Walter Roberson

### Walter Roberson (view profile)

on 10 Nov 2018
Delaying 4*pi*t by an integer t results in exactly the same value. cos 4*pi*t is periodic with a period of 1/2 so delaying it by 10 has no effect on the value.
Now if you were to take x(t-10.3) for example... Well, you would not be able to tell the difference compared to x(t-0.3) but it would be different than x(t)

### Tags

on 10 Nov 2018

f1 = 2;
f2 = 3;
t=linspace(0,1,1000)
x=cos(2.*pi.*f1.*t)
x1=cos(2.*pi.*f2.*(t-10))
subplot(2,1,1);
plot(t,x);
subplot(2,1,2);
plot(t,x1);