Trig identities (reference)
Common identities summary.
Calculator
How to use
Reference
Not a symbolic prover.
Educational use only. For assessments, show reasoning and check boundary cases.
Common identities summary.
Not a symbolic prover.
Educational use only. For assessments, show reasoning and check boundary cases.
Model / formula
Common identities (reference)
Summary
sin²θ + cos²θ = 1 1 + tan²θ = sec²θ sin(A±B) = sin A cos B ± cos A sin B cos(A±B) = cos A cos B ∓ sin A sin B sin 2θ = 2 sin θ cos θ cos 2θ = cos²θ − sin²θ