Choose an identity, enter an angle θ, and see both sides evaluated numerically. The LHS and RHS are also graphed as separate curves — when they overlap perfectly, the identity is verified.
sin²θ + cos²θ = 1
tan²θ + 1 = sec²θ (divide by cos²θ)
1 + cot²θ = csc²θ (divide by sin²θ)
All three Pythagorean identities come from dividing x² + y² = r² by different terms. On the unit circle (r=1), this gives sin²θ + cos²θ = 1 directly.
A live tutor can walk you through each identity proof step by step, from the Pythagorean identities to double-angle forms.