# Fourier series (2 same functions different inequality signs)

1. Feb 13, 2013

### izen

1. The problem statement, all variables and given/known data

these two functions will give the same Fourier series? because when I write the graph they look the same?

2. Relevant equations

3. The attempt at a solution

in the picture

thank you
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Feb 13, 2013

### jbunniii

The series coefficients are defined by an integral. If you change the value of a function at a finite number of points, can the integral give you a different result?

3. Feb 13, 2013

### izen

I think integral give a different result so they are different ? not 100% sure

because in my lecture note all the example are < ,> there is no single example has <=, >=. so when I tried to do some exercise there are <=, >= on the functions so it kinda confused me. please explain more

Last edited: Feb 13, 2013
4. Feb 13, 2013

### jbunniii

No, you can change a function at a finite number of points, and the integral will still be the same. So your Fourier coefficients will be the same for both functions.

5. Feb 13, 2013

thank you