Question

How do you use substitution to integrate `4x( x^2 + 3)^4 dx`?

Answer 1

`2/5(x^2+3)^5+C`

Explanation:

Substitute `x^2+3 = u`. Then `2xdx = du`.

So

`int 4x( x^2 + 3)^4 dx = int 2u^4 du = 2/5u^5+C`
`qquad = 2/5(x^2+3)^5+C`