edited: x = cos2 2θ seems to work
4 Answers
" ____________
·2010-01-30 01:03:20
\int \frac{dx}{ 1+ \sqrt{x}.\sqrt{x}.\sqrt{1- x}}
\sqrt{x} = t
on differentiating
\frac{1}{2\sqrt{x}} dx = dt
now integral becomes
2 \int \frac{dt}{( 1 + t ) . \sqrt{1- t^2 }}
now put ----1 + t = \frac{1}{z} \Rightarrow t = \frac{1}{z} -1 = \frac{1- z}{z}
dt = \frac{-1}{z^2 }
integral reduces to
- 2\int \frac{dz }{\sqrt{2z - 1}} = - 2 \sqrt{2z - 1}
now put the value of z we get answer as
\frac{2(\sqrt{x}-1)}{\sqrt{1 - x}} + c
hope this helps but hari sir 's method is very nice and ShOrT