Key Equations - Precalculus

arc length	$s = r θ$
area of a sector	$A = \frac{1}{2} θ r^{2}$
angular speed	$ω = \frac{θ}{t}$
linear speed	$v = \frac{s}{t}$
linear speed related to angular speed	$v = r ω$

Cofunction Identities

\begin{array}{l} \begin{array}{l} \cos t = \sin (\frac{π}{2} - t) \end{array} \\ \sin t = \cos (\frac{π}{2} - t) \\ \tan t = \cot (\frac{π}{2} - t) \\ \cot t = \tan (\frac{π}{2} - t) \\ \sec t = \csc (\frac{π}{2} - t) \\ \csc t = \sec (\frac{π}{2} - t) \end{array}