How do you integrate int x(1-x^2)^(1/4)dxx(1x2)14dx?

1 Answer
Apr 6, 2018

intx(1-x^2)^(1/4)dx=-2/5(1-x^2)^(5/4)+Cx(1x2)14dx=25(1x2)54+C

Explanation:

A substitution will do.

u=1-x^2u=1x2

(du)/dx=-2xdudx=2x

du=-2xdxdu=2xdx

We see xdxxdx shows up in the integral. So, solving the above for xdxxdx yields

-1/2du=xdx12du=xdx

We then have

-1/2intu^(1/4)du=-1/2(u^(5/4)/(5/4))+C=(-1/2)(4/5)u^(5/4)+C=-2/5u^(5/4)+C12u14du=12(u5454)+C=(12)(45)u54+C=25u54+C, as intx^adx=x^(a+1)/(a+1)+Cxadx=xa+1a+1+C

Rewriting in terms of xx yields

intx(1-x^2)^(1/4)dx=-2/5(1-x^2)^(5/4)+Cx(1x2)14dx=25(1x2)54+C