Trigonify

Cofunction

sin/cos

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

Related Cofunction identities

cos/sintan/cot

Study this and 44 more identities in the Trigonify workspace — an interactive unit circle, a step-by-step triangle solver, quizzes, and a practice problem bank.