# Integration - Trig Substitutions (solve for Y)

1. Oct 30, 2007

### MeanGreen07

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

Solve the problem for y as a function of x

a) $$(x^2+1)^2 \frac{dy}{dx}=\sqrt{x^2+1}$$

2. Relevant equations

3. The attempt at a solution

After some simplifying, I get here but get stuck:

Did I go the wrong route going for the U sub? Were my calculations wrong to begin with? Any help is greatly appreciated!!!!!

Last edited: Oct 31, 2007
2. Oct 30, 2007

### Dick

You are on the right track. But the tex is hugely unclear. In the end the integral should have come out to be dtheta/sec(theta). And that's hugely easy.

3. Oct 30, 2007

### Dick

Stop texing. Your integrand is 1/sec(t)^3 and the dx is sec(t)^2*dt.

4. Oct 31, 2007

### MeanGreen07

Sorry guys. My texing was bad and it appears my question was too simple for these forums.

5. Oct 31, 2007

### Dick

Hey, hey. Sorry. I wasn't criticizing you. I can't TeX for s**t either. I'm just saying the problem is easier than you think. You just didn't put the integrand together with the dx and get a simple solution.

6. Oct 31, 2007

### MeanGreen07

Well, I feel somewhat better. LOL!!

Thanks for the help!