- #1

td21

Gold Member

- 178

- 8

## Homework Statement

[tex]\cos (\frac{(-1)\pi x}{L})-\cos (\frac{3\pi x}{L})[/tex]

## Homework Equations

## The Attempt at a Solution

the first cosine is the same as positive but is the second cosine simply equal to

[tex]\cos (\frac{\pi x}{L})[/tex]?

thanks!