Struggling to Solve \int\sqrt{\frac{x}{x^2+2}}dx

  • Thread starter Thread starter zillac
  • Start date Start date
zillac
Messages
4
Reaction score
0

Homework Statement



Find \int\sqrt{\frac{x}{x^2+2}}dx

Homework Equations



N/A

The Attempt at a Solution


Don't know where to start.
I tried a few substitution but doesn't yield anything.
It seems to be short, so any small hint will be great.
Thanks!
 
Physics news on Phys.org
The answer isn't pretty at all. Try it out at integrator.wolfram.com There's an imaginary number in it, along with "elliptical integrals", whatever that may mean. Probably there isn't any antiderivative which you can express in elementary form.
 
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...
Back
Top