## jaersyn 3 years ago integrate 1/(5+sinx-3cosx) let u = tan(x/2) cosx = (1-u^2)/(1+u^2) sinx = 2u/(1+u^2) dx = 2/(1+u^2)

1. Dido525

Oh my god... This is a monster to integrate...

2. jaersyn

yeah, after substituting everything i got up to 1/[4(u+(1/8))^2 + (15/64)]

3. jaersyn

if you could help me with that, that'd be cool. I don't know what to do next to integrate

4. Dido525

You don't have to use intergration by parts. You can use substitution twice.

5. jaersyn

?

6. Dido525

Nevermind. I am wrong.

7. Dido525

Dammit. Sorry. I can't solve this :( . It's beyond my level of math.

8. jaersyn

quick unrelated question: if i have 1/u(1-u^2) can i use partial fractions to integrate? even though its (-u^2 + 1) in the denom? i never came across a negative like that

9. Dido525

I don't think so... Sorry. I can't help you any further with this :( .

10. jaersyn

that's okay, thanks for looking though

11. jaersyn

i know igbasallote got dis

12. jaersyn

level 99 math wizard

13. Dido525

I would love to see how to do this question.

I GOT IT, BUT VERY LONG TO WRITTING THIS STEPS :(

as information (if im not mistake), i got the answer : |dw:1349498667471:dw|