Integration using separation of parts

[crazco]

Homework Statement

evaluate the integral cos^-1 2x dx?

Homework Equations

The Attempt at a Solution

let

u = arc cos
du = -1 / (sqrt 1-x^2)
dv = 2x
v= x^2

arc cos * x^2 - the integral of -x^2 / (sqrt 1-x^2)

then i don't know what to do

 

[rock.freak667]

The Attempt at a Solution

let

u = arc cos
du = -1 / (sqrt 1-x^2)
dv = 2x
v= x^2

arc cos * x^2 - the integral of -x^2 / (sqrt 1-x^2)

then i don't know what to do

What you have is ∫cos^-1(2x) dx

so u = cos^-1(2x) and dv=dx

 

[HallsofIvy]

This is NOT "arccos" multiplied by 2x!