KnowraPythagorean trigonometric identityLinked fromLinked fromThe 3 pages that link to Pythagorean trigonometric identity, each with the reason it gives.All 3Broader topic 1Related 2TangentRelated: Dividing it by cos²(x) yields 1 + tan²(x) = sec²(x).Trigonometric identityBroader topic: It is the central relation from which several standard identities follow.Trigonometric substitutionRelated: The identities make radicals such as √(1 − sin²θ) simplify to trigonometric functions.