Question

How do you integrate by substitution `int(x^2-9)^3(2x)dx`?

Answer 1

`(x^2-9)^4/4+c`

`y=x^2-9`

Explanation:

`y=x^2-9`

`dy=2xdx`

`int(x^2-9)^3(2x)dx=inty^3dy=y^4/4+c=(x^2-9)^4/4+c`