section_path: Identities/Trigonometric identities/Pythagorean identities
section_name: Pythagorean identities
paragraph_text: Pythagorean identities
  
  The following trigonometric identities are related to the Pythagorean theorem and hold for any value:
  
  The second and third equations are derived from dividing the first equation by cos 2 A {\displaystyle \cos ^{2}{A}} and sin 2 A {\displaystyle \sin ^{2}{A}}, respectively.