# LTI System Problem

How do you represent the Fourier transform of a periodic signal as the input in a LTI system?
More precisely, a sequence of triangle pulses symmetric to the origin.

I know what the Fourier transform is 2\pi (sum (Xn delta(omega - (n)omega0)))

I was told to reduce the Xn to constants, but can't figure how to reduce the n omega0.

## The Attempt at a Solution

$X(n)=\frac{1}{T}\int_{t_0}^{t_0+T} f(n)e^{-i2\pi nt/T}$