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## Homework Statement

Integrate dx/((x^2+1)^2)

## Homework Equations

Tan^2=sec^2-1

## The Attempt at a Solution

So I let x=tanx then dx=sec^2x

Then plugging everything in;

Sec^2(x)/(tan^2+1)^2

So it's sec^2/(sec^2x)^2) which is sec^2x/sec^4x

Canceling out the sec^2 gives you

1/sec^2x

Integrate: ln(sec^2x)+C

Is that right?