Table of Trigonometric Identities

A website I frequent when looking for trigonometric identities and properties

Table of Trigonometric Identities

Some of the ones I often use:

\[ \sin^2 \phi + \cos^2 \phi = 1 \]

\[1 + \tan^2 \phi = \sec^2 \phi \]

\[ 1 + \cot^2 \phi = \csc^2 \phi \]