In Fourier Series, is An term paired with odd function or even function?
This is I have done so far
Thanks for your help

 

What is An?

What do you mean "paired with" odd function or even function?

 

if the function is odd, do we calculate bn or An?

 

You are asking questions without defining your terms. What is An? What is bn?

Don't assume that every text on Fourier series use the same letters to mean the same things.

 

I thought an and bn terms are common notation.

 

They are reasonably common, but some texts associate one with the sine and some the other with the sine.

But even if that weren't the case, you are asking a question on a forum trying to get help from people that, in many cases, haven't worked with that notation for many, many years. If you don't define your terms, you are basically saying that you are expecting others to dig out a reference to refresh themselves on notation in order to help you. Most people simply aren't going to jump through those hoops in order to help someone else with their homework when the person asking help obviously doesn't care enough about getting help to even make the attempt to make it easy for others to help them.