Posted by Jillian on Tuesday, January 20, 2009 at 3:57pm.
Prove the identity.
sin² θ = tan² θ / 1 + tan² θ

Math  drwls, Tuesday, January 20, 2009 at 4:37pm
I assume the right side is supposed to be tan² è /(1 + tan² è)
Start by rewriting
1 + tan^2 = (cos^2 + sin^2)/cos^2
= 1 /cos^2
so that
1/(1+tan^2) = cos^2
Therefore the right side becomes
(sin^2/cos^2)* cos^2 = sin^2 
Math  Jillian, Tuesday, January 20, 2009 at 4:46pm
how did 1 + tan^2 become cos^2 + sin ^2?

Math  Jillian, Tuesday, January 20, 2009 at 4:54pm
oh nevermind i got it thank you.

Math  Jillian, Wednesday, January 21, 2009 at 5:45pm
Cool