Trigonify

Cofunction

cos/sin

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

Related Cofunction identities

sin/costan/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.