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

## Answer This Question

## Related Questions

- Math - Calculus - The identity below is significant because it relates 3 ...
- precalculus - sinθ=12/13, θ lies in quadrant II. Find the exact value...
- math - The Pythagorean Theorem gives the relationship between the sides of a ...
- Trig - Verify the given equations: ____1______ + ____1_______ = -2 tanθ tan...
- trig help much appreciated! :)) - 1. Find the complete exact solution of sin x...
- AP Physics I - A placekicker is about to kick a field goal. The ball is 26.6 m ...
- geometry - Suppose θ is an angle strictly between 0 and π 2 such that ...
- algebra!!!! please help me!!!! - Suppose θ is an angle strictly between 0 ...
- PHYSICS - A placekicker is about to kick a field goal. The ball is 20.1 m from ...
- Pre-calc - Use the given information to determine the values of sinθ, cos&#...

More Related Questions