# Sampling frequencies

## Homework Statement

We have the following signal frequencies:

f1=18 Hz, f2=510 Hz, f3=1100 Hz

when using the sampling frequency fs=1000 Hz.

how would these signals be like?

my question is if I could use the same formula stated below for all the frequencies f1,f2,f3.. because the second and third ones are above the Nyquist Frequency fc=fs/2=500 Hz so there would be aliasing in this case.

and what about the graphs for these samplings?

## Homework Equations

when using another sampling frequency fs=1002 Hz

and here also would be the same questions.

## The Attempt at a Solution

I used the formula:

$$S_{\Delta }(v)= f_{s}\sum_{n=-\infty}^{+\infty}(S(v-n*f_{s}))$$

for the first frequency f1= 18 Hz I had:

$$S_{\Delta}(18)=1000\sum(S(18-n*1000))$$

where $$n=-\infty$$ to $$+\infty$$

haruspex