Pythagorean Identities

${\sin }^2\theta +{\cos }^2\theta =1$ $1-{\cos }^2\theta ={\sin }^2\theta$ $1-{\sin }^2\theta ={\cos }^2\theta$ ${\sec }^2\theta -{\tan }^2\theta =1$ $1+{\tan }^2\theta ={\sec }^2\theta$ ${\sec }^2\theta -1={\tan }^2\theta$ ${\csc }^2(\theta )-{\cot }^2(\theta )=1$