How Can You Perform Fourier Transform of a Composite Function in MATLAB?

[frenzal_dude]

Homework Statement

I need to find the Fourier Transform of g(t) using matlab,

$$g(t) = tri(\frac{t}{2\pi })Cos(2\pi (\frac{5}{\pi })t)$$

Homework Equations

How can this be done accurately since you need 't' to be from -infinity to +infinity?

And how can you input a tri function in matlab?

The Attempt at a Solution

I tried using y=trimf(t,[3 6 8]); but when I multiply the trimf function and the cos function it says the matrices must have the same dimensions.

Thanks for your help.

 

[KataKoniK]

Hello,

To accurately find the Fourier Transform of g(t), you will need to use the continuous Fourier Transform formula, which involves integrating from -infinity to +infinity. However, for practical purposes, you can use a finite range of values for t and still get a good approximation of the Fourier Transform.

To input a triangular function (tri) in matlab, you can use the trimf function as you have already tried. However, to multiply it with the cosine function, you will need to make sure that the dimensions of the matrices are the same. You can do this by either using the same range of values for t in both functions or by using the same number of elements in t for both functions.

I hope this helps. Let me know if you need further clarification.