Proving Equation: tan^2θ - sin^2θ = tan^2θsin^2θ

[Spahrtacus]

Homework Statement

Prove that tan^2θ - sin^2θ = tan^2θsin^2θ

Homework Equations

I'm not sure :S

The Attempt at a Solution

I have no idea

 

[Kurdt]

What is the definition of tan?

 

[Spahrtacus]

tan = sin^2θ/cos^2θ

?

 

[Kurdt]

$$\tan (\theta) = \frac{\sin(\theta)}{\cos(\theta)}$$

so

$$\tan^2 (\theta) = \frac{\sin^2(\theta)}{\cos^2(\theta)}$$

You will then need to manipulate one side until it equals the other using basic trigonometric identities.