# Math Help - Prove Id

1. ## Prove Id

sec^2 = 1 + tan^2

or

csc^2 = 1 + cot^2

2. Originally Posted by reallylongnickname
sec^2 = 1 + tan^2

or

csc^2 = 1 + cot^2
Just divide the Pythagorean identity by cosine

$\sin^2(x)+\cos^2(x)=1 \iff \frac{\sin^2(x)}{\cos^2(x)}+\frac{\cos^2(x)}{\cos^ 2(x)}=\frac{1}{\cos^2(x)}$

Now just simplify

See if you can get other one

3. $csc^2(x) = 1 + cot^2(x)\longleftrightarrow \frac{1}{ sin^2(x)}-\frac{cos^2(x)}{sin^2(x)} = 1$