Question

eval the integral

integrate x^3 (sqrt x^4+2) dx

Answer 1

I think a U-substitution will work here.

Answer 2

Is the +2 also in the square root?

Answer 3

Try substituting u=x^4+2

Answer 4

yes 2 is also in sort

Answer 5

can you give me step by step so I know exactly what to di cuz I'm a little confused w/ U sub

Answer 6

Ah, ok. The first step is to see that you have both x^3 and x^4 in the function and 4x^3 is the derivative of x^4.

If you let u=x^4+2, then du = 4x^3 dx

The function you are integrating is then \(\large (1/4)u^{1/2} du \)

Answer 7

how did you get 1/4?