Trigonometry
Basic

Pythagorean Identity

The fundamental trig identity from the unit circle.

Formula

sin2θ+cos2θ=1\sin^2\theta + \cos^2\theta = 1

Variables

\thetaAngle

Example

If sinθ=0.6, cosθ=0.8

Did You Know?

sin²θ + cos²θ = 1 is literally the Pythagorean theorem applied to the unit circle.