The following equations are eight of the most basic and important
trigonometric identities. These equations are true for any
angle. From them, countless additional
identities can be formed. These eight should be memorized.
csc(θ) =  |
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sec(θ) =  |
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cot(θ) =  |
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tan(θ) =  |
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cot(θ) =  |
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(sin(θ))2 + (cos(θ))2 = 1 |
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1 + (tan(θ))2 = (sec(θ))2 |
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1 + (cot(θ))2 = (csc(θ))2 |
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