2 Integral & 1 exponental problem.

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Homework Statement


Pictures courtesy of my ms paint skills.
1.http://img38.imageshack.us/img38/6023/problemb.png
2.http://img32.imageshack.us/img32/7499/problem2o.png
3.http://img44.imageshack.us/img44/5445/problem3.png
These problems are so easy I hardly ever see them or get to apply there rules. So I need see if I'm doing these few problem right.

Homework Equations


1. use a/b+c 2. use a+b/c

The Attempt at a Solution


1. x+(x^2/2)
2.x+lnx(e^x^2)^2= e^2x^2

I await your responses thanks.

Homework Statement


Homework Equations


The Attempt at a Solution

 
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One way to learn to try some website like below:-
http://integrals.wolfram.com/index.jsp

then rework your solutions with the tools you have learnt.
simplify the difficult part into simpler ones and work on it.

Wanna try first? Thanks
 
You're a bit off on 1 and 2. For 1, the trick is to add and subtract 1 from the numerator and then divide. Knowing the antiderivative of 1/(1+x^2) is helpful here.

For 2, just divide, which is what you seemed to have done. But the antiderivative of 1/x^2 is not ln(x).

For 3, if all you have to do is simply, then yes you should get e^(2x^2).
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...

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