Question

how to integrate
sin θ dθ/(cos^2 θ +1)

Answer 1

\[\int\limits\frac{\sin\theta}{\cos^{2}\theta+1} d\theta \]
let u = cosx =>\(\frac{du}{-sinx} \)
so..
\[\int\limits\frac{-1}{u^{2}+1} \]
Then integrate it..its an inverse trig function.

Answer 2

woops typo;
let u = \(\cos\theta \) => \(\frac{du}{-\sin\theta} \)

Answer 3

then you have to use the substitution

u = tan
du = sec^2

Answer 4

um..why?

Answer 5

to integrate
1/(u^2 +1)

Answer 6

Mimi, Sorry to ask an off topic question, but did you write those equations using Latex?

Answer 7

Its an inverse trig function.
\[\int\limits\frac{1}{a^{2}+x^{2}} dx = \frac{1}{a} \tan^{-1} \frac{x}{a} \]

Answer 8

Yes, I did.

Answer 9

oh wait, sorry i forgot, was going to solve it from scratch :)

Answer 10

Mimi, Very cool. Thanks.

Answer 11

Oh, it will be harder i suppose..