Why am I wrong? [Math].

[CrackaLackaZe]

Can anyone tell me why integration of [-1 + 1/(1+x) + 1/(1-x) dx] = [-x + ln(1+x) - ln(1-x)]

I thought it'd be [-x + ln(1+x) + ln(1-x)]...............................................but ^ is what the book says.

 

[BigPoppa]

Books are wrong, often. Also, thats a sign change error. Double check your signs on your calculations, you'll find the problem there.

 

[maziwanka]

Originally posted by: CrackaLackaZe
Can anyone tell me why integration of [-1 + 1/(1+x) + 1/(1-x) dx] = [-x + ln(1+x) - ln(1-x)]

I thought it'd be [-x + ln(1+x) + ln(1-x)]...............................................but ^ is what the book says.

well,

int(1/(1-x)) = -ln(1-x), youre forgetting the chain rule.

 

[nebula]

Since you're ? is already answered...

But if you want a nice little book that takes your huge clac. book and condenses it to just what you need to know, check this out: How To Ace Calculus

It's cheap and I found it to be a nice refresher.

edit: fixed link, I think

 

[CrackaLackaZe]

int(1/(1-x)) = -ln(1-x), youre forgetting the chain rule.

Doh...I knew it was something retarded like that....thx. It was the last part of a really long problem.