# Search results

1. ### Finding the coeffiecients of a sine series for -3*cos(8*pi*x/L)

I'm sorry if I came off as offended and defensive. I wasn't trying to. I did notice after that you had the same identity written down as tiny tim, but I had already posted twice and didn't want to go back and post again. I'll respond more carefully in the future so this doesn't happen again.
2. ### Finding the coeffiecients of a sine series for -3*cos(8*pi*x/L)

Worked perfectly! Thanks alot.
3. ### Finding the coeffiecients of a sine series for -3*cos(8*pi*x/L)

I am aware of the orthogonality relations, however I am not familiar with how they are derived, that is not covered in my textbook unfortunately. I do know that sin and cos are orthogonal on the interval -L to L, but they are not orthogonal on the interval 0 to L (according to my text), so this...
4. ### Finding the coeffiecients of a sine series for -3*cos(8*pi*x/L)

Homework Statement all i really need to do is solve the integral: \int-3*sin(\frac{n*pi*x}{L})*cos(\frac{8*pi*x}{L}) from x=0 to x=L Homework Equations The Attempt at a Solution I'm not very sure where to start with this. Any help would be appreciated.