Trigonify

Topics · 3 identities

Cofunction

Complementary-angle identities linking each function to its cofunction.

sin/cos

sin⁡(π2−θ)=cos⁡θ\sin(\tfrac{\pi}{2} - \theta) = \cos\theta
Open identity

cos/sin

cos⁡(π2−θ)=sin⁡θ\cos(\tfrac{\pi}{2} - \theta) = \sin\theta
Open identity

tan/cot

tan⁡(π2−θ)=cot⁡θ\tan(\tfrac{\pi}{2} - \theta) = \cot\theta
Open identity