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Pythagorean Identities formula

sin ²X + cos ²X = 1

1 + tan ²X = sec ²X

1 + cot ²X = csc ²X

sin²θ + cos²θ = 1 is called a Pythagorean Identity.

From the identity we can creat two additional Pythagorean Identities: tan²θ + 1 = sec²θ;
1 + cot²θ = cosec²θ.

For example, when θ = 19º, Then Sin² + Cos² = 0.3255681544571568² + 0.9455185755993167², Sin² + Cos² = 0.10599 + 0.89401, 1 = 1. Since 1 = 1, we have proven this Trigonometry Identity using the angle 19º