Sine of Three Right Angles less Angle

Theorem

 * $\sin \left({\dfrac {3 \pi} 2 - \theta}\right) = -\cos \theta$

where $\sin$ and $\cos$ are sine and cosine respectively.

Also see

 * Cosine of Three Right Angles less Angle
 * Tangent of Three Right Angles less Angle
 * Cotangent of Three Right Angles less Angle
 * Secant of Three Right Angles less Angle
 * Cosecant of Three Right Angles less Angle