Trigonometry
Intermediate

Identity: 1 + tan² = sec²

Derived Pythagorean identity dividing by cos².

Formula

1+tan⁡2θ=sec⁡2θ1 + \tan^2\theta = \sec^2\theta

Variables

\thetaAngle

Did You Know?

This identity is just the Pythagorean theorem in disguise, divided through by cos².

identitypythagorean