Problem with Integral question

  • Thread starter Thread starter kasse
  • Start date Start date
  • Tags Tags
    Integral
kasse
Messages
383
Reaction score
1
If I know that \int^{\pi /2}_{0}x^2 cos^2 x dx = \frac{\pi^3}{48} - \frac{pi}{8} can I use this to calculate \int^{\pi / 2}_{- \pi /2} u^2 cos^2 u du?
 
Physics news on Phys.org


Obviously, since the integrand is even, the latter integral is just twice the first.
 
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