# Integration Trouble

1. Nov 15, 2008

### WiFO215

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

$$\int$$ $$\sqrt{a^{2}-x^{2}}$$$$/$$$$x*\sqrt{x^{2}-b^{2}}$$

3. The attempt at a solution

I tried all sorts of substitutions and none work. Please help me.

Last edited: Nov 15, 2008
2. Nov 15, 2008

### HallsofIvy

Staff Emeritus
Would it help to know that
$$\frac{a^2- x^2}{x^2- b^2}= \frac{b^2- a^2}{x^2- b^2}- 1$$

3. Nov 15, 2008

### WiFO215

Edit notice: I multiplied the integrand by 1/x. Its not to the xth root of. I didn't type that in first type.

4. Nov 15, 2008

### WiFO215

I don't have a clue how that helps HallsofIvy.

5. Nov 15, 2008

### WiFO215

Mathematica says this rubbish can't be solved.

6. Nov 15, 2008

### HallsofIvy

Staff Emeritus
Have you editted the first post? I didn't notice that "x" outside the square root before.
Let u= x2- b2 so that du= 2xdx
$$\sqrt{\frac{b^2-a^2}{x^2- b^2}-1}= \sqrt{\frac{A}{u}- 1}$$

7. Nov 16, 2008

### WiFO215

Yes. I edited the first post. Forget it though. I think what I did is wrong anyway.