# How the ? (Integration / Somewhat Urgent)

1. Integrate on the interval [0, 1]: (x2 - 1)/(x2 + 1)

2. No relevant equations.

3.

S x2/(x2 + 1) - [S 1/(x2 + 1)] =

S (x2 + 1) - 1/(x2 + 1) - [(arctan x)] =

S -1 - [(arctan x)] =

-x - arctan x

I can plug in the numbers on my own, but I would like to know if what I've done so far is correct...

- Lunar Guy

Last edited:

Related Calculus and Beyond Homework Help News on Phys.org
How does ((x2 + 1) - 1)/(x2 + 1) become -1?

a.a
the (x^2 + 1) cancles
but where did u get x2/(x2 + 1) from?
x^2 - 1 = x - 1)(x+1)

the (x^2 + 1) cancles
but where did u get x2/(x2 + 1) from?
x^2 - 1 = x - 1)(x+1)
The (x2 + 1) cancels to become 1 - (1/(x2 + 1)), not -1.
He got x2/(x2 + 1) from (a + b)/c = a/c + b/c.

a.a
so how does x^2/(x^2 +1) reduce to x^2 +1?

so how does x^2/(x^2 +1) reduce to x^2 +1?
That never happened. He skipped the step x2 = x2 + 1 - 1.

Think its quite easy... Convert the neumerator in the form of the denominator by writing -1 as 1-2

So now you get (xsquare + 1) - 2