Trigonometric Relations and Identities

Reciprocal relations

cosec θ = 1/sin θ
sec θ = 1/cos θ
cot θ = 1/tan θ

Unit relations

cosec θ sin θ = 1
sec θ cos θ = 1
cot θ tan θ = 1

Quotient Relations

tan θ = sin θ/cos θ
cot θ = cos θ/sin θ

Square Relations

sin2 θ + cos2 θ = 1
sec2 θ = 1 + tan2 θ
cosec2 θ = 1 + cot2 θ

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