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## Homework Statement

Sorry for all the posts; I'm trying to study for a test tomorrow.

1. Integrate

[tex]\int\frac{dx}{x^2+8x+65}[/tex]

2. Integrate

[tex]\int\frac{2x^3}{\sqrt(x^2+4)}dx[/tex]

## Homework Equations

## The Attempt at a Solution

1.

[tex]u = x^2 + 8x + 65[/tex]

[tex]du = 2x+8dx[/tex]

Stuck.

2.

[tex]\int2x^3(x^2+4)^{-\frac{1}{2}} dx[/tex]

[tex] \frac{2x^4}{4}\frac{x^2+4}{\frac{1}{2}} + C[/tex]

Not sure if this is right so far.

Thanks for any help!