The Basic Trig Functions
Some Definitions
First let's define the six trig functions:
sine, cosine, tangent, secant, cotangent and cosecant, and see what
they have to do with triangles.
The mnemonic SOH-CAH-TOA captures the definitions of the three most
common trig functions, at least for angles between 0 and π/2 radians (90 degrees).
Sine =OppositeHypotenuse
Cosine =AdjacentHypotenuse
Tangent =OppositeAdjacent
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The other trig functions are defined in terms of first three:
Secant =1Cosine=HypotenuseAdjacent
Cosecant =1Sine=HypotenuseOpposite
Cotangent =1Tangent=AdjacentOpposite
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Below is how to find them in the unit circle.
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