For the following integral find an appropriate TRIGONOMETRIC SUBSTITUTION of the form x=f(t) to simplify the integral.

INT x(sqrt(8x^2-64x+120))dx

x=?

1 answer

You could try the similar technique as:
http://www.jiskha.com/display.cgi?id=1260825344

In this case, it is a multiplication, so the result is slightly different.
However, after completing the squares, you will get the form
let y=x-4, x=y+4
(1/√8)(y+4)*sqrt(y^2-1)
which should still be mangeable.