from fourier transform to fourier series

HI,

I really need to find a relationship between the coefficients of the Fourier transform coefficients and those for Fourier series, especially** how to find Fourier series coefficients from the Fourier transform coefficients**.

The teacher talks about this in class but wants us to find the formula by ourselves.

The formula should be like this:

an= X1*(Fn)+X2*(F-n)

bn= X3*(Fn)+X4*(F-n)

Where an and bn are the Fourier series coefficients for cosine and sine respectively. Fn are the Fourier transform coefficients.

FinallyX1,X2,X3,X4 are some coefficients( I don't know if they are constant or not)

I could not derive it by myself and did some research with books and online but I have not found something good.

Please can some help me please?

Thank you

B