# Homework Help: Integration with Sines and Cosines

1. Feb 25, 2010

### Ayesh

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

$$\int$$sinxcosx/sin^4x+cos^4x

2. Relevant equations

sin^2x=1/2-1/2cos(2x)

cos^2x=1/2+1/2cos(2x)

sinxcosx=1/2sin(2x)

3. The attempt at a solution

$$\int$$1/2 sin(2x)/(1/2-1/2cos(2x))^2 + (1/2 + 1/2cos(2x))^2

$$\int$$1/2 sin(2x)/1/2 + 1/2cos^2(2x)

...?

Am I on the right track?

2. Feb 25, 2010

### tiny-tim

Hi Ayesh!

(have an integral: ∫ and try using the X2 tag just above the Reply box )

Yes, that's fine.

(though it would have been quicker to notice that the original denominator is almost the square of cos2x + sin2x )

And you should be able to integrate it immediately.

3. Feb 26, 2010

Thank you!