Integration of y * sqrt function

[Emilyd]

Homework Statement

given: 3/8 * ∫ (y^3) *√((y^4)+9) dy the integral is from 0 - 2

Homework Equations

The Attempt at a Solution

I have attempted the problem so far, it was a double integration and it is right up to here. I just can't figure out how to integrate this part.

 

[Mark44]

Homework Statement

given: 3/8 * ∫ (y^3) *√((y^4)+9) dy the integral is from 0 - 2

Homework Equations

The Attempt at a Solution

I have attempted the problem so far, it was a double integration and it is right up to here. I just can't figure out how to integrate this part.

Looks like an ordinary substitution would work - u = y^4 + 9 ==> du = 4u^3*du

 

[Emilyd]

Thankyou! worked a treat.

 

[Mark44]

So if you're working with double integrals and having trouble with ordinary substitutions, I would advise you to go back and review the integration techniques such as substitution, trig substitution, integration by parts, and partial fractions.