Cofunction identities - Trigonometric Identities

Notes:

Cofunction Identities: Basically, we need the sum of the left and right brackets to be 90° or $\frac{\pi}{2}$

$\sin(\frac{\pi}{2}-\theta)=\cos(\theta)$
$\sin(\theta)=\cos(\frac{\pi}{2}-\theta)$
$\tan(\frac{\pi}{2}-\theta)=\cot(\theta)$
$\tan(\theta)=\cot(\frac{\pi}{2}-\theta)$
$\sec(\frac{\pi}{2}-\theta)=\csc(\theta)$
$\sec(\theta)=\csc(\frac{\pi}{2}-\theta)$