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## Pythagorean Identities

#### High School Functions - HSF-TF.C.8

What Are Pythagorean Identities? Pythagorean identities are the true representation of Pythagoras theorem as functions. So, these identities can also help us in deciding fundamentally deciding the relationship between sine, cos and tan trigonometric functions. You can determine from that point the functions of other identities in our lives and how they can make things easy and simple too. Pythagorean identities are trigonometric identities, which are extensions of the Pythagorean theorem. The fundamental identities state that for every angle: sin2 Θ + cos2 Θ = 1 Pythagorean identities are extremely useful for simplifying trigonometric expressions, particularly in writing expressions as functions of either sine or cos in the statements of double angle formulas. There are there Pythagorean identities that you need to recall immediately. The first one is already mentioned above. The rest of the two are: 1 + cot2 Θ = csc2 Θ and 1 + tan2 Θ = sec2 Θ Students can use these worksheets and lessons to learn techniques that help them determine missing value in trig. functions.