Master Integrals with Substitution: Simplifying Tricky Integrals in Calculus

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∫dx
--------------------- (divide by)
(x2+a2)3/2

Tried integrating with substitution with U = x2+a2)
Then dU = 2xdx
x = √(U-a2)

Leaving me with dU/ (2x) (U)3/2
= ∫dU/2
-----------------------
√(u-a2))(U)3/2

But that doesn't help either.

Do I need to use a table? Thanks for any help.
 
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You can use that 1/(1+tan^2(θ))=cos^2(θ)

Substitute x/a=tan(u).

ehild
 
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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