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Module 3: Quick Reference
Trig Functions of Any Angle
Reciprocals
csc = 1/sin
sec = 1/cos
cot = 1/tan
Quotients
tan = sin/cos
cot = cos/sin
Pythagorean Identities
sin²θ + cos²θ = 1
1 + tan²θ = sec²θ
1 + cot²θ = csc²θ
Even-Odd
Even: cos, sec
Odd: sin, tan, csc, cot
Cofunctions (θ + co = 90°)
sin θ = cos(90°−θ)
tan θ = cot(90°−θ)
sec θ = csc(90°−θ)
Coordinate Definition
sin = y/r cos = x/r tan = y/x where r = √(x²+y²)