caranya gmn nih? bantu dong..

f (x) = x / V(1- x^2)
f (x) = x (1 - x^2)^-1/2
J x (1 - x^2)^-1/2 dx
misal u = 1 - x^2
du/dx = -2x
dx = du/-2x
J x (u^-1/2) du / -2x
= -1/2 J u^-1/2 du
= -1/2 .u^(-1/2+1) / (-1/2+1) + c
= -1/2.u^1/2 / 1/2 + c
= - u^1/2 + c
= - V(1- x^2) + c...(a)