# The period of a function is the number, T, such that f ( θ+ T ) = f( θ). Trig Cheat Sheet Definition of the Trig Functions 2 Right triangle definition For this definition we assume that 0 2 << or 0 90°< < °. So, simply put, Trigonometry is the study of the measures of triangles. − 1 ≤ sin θ≤ 1 csc θ≥ 1 and csc θ≤ − 1 − 1 ≤ cos θ≤ 1 sec θ≥ 1 and sec θ≤ − 1 −∞ ≤ tan θ≤ ∞ −∞ ≤ cot θ≤ ∞ What is Trigonometry The word Trigonometry comes from the Greek trigonon (meaning triangle) and metron (meaning measure). # The range is all possible values to get C: Cosine and its reciprocal, secant, are. T: Tangent and its reciprocal, cotangent, are positive. S: Sine and its reciprocal, cosecant, are positive. sin θ, θ can be any angle cos θ, θ can be any angle tan θ , Reading around the quadrants, starting with QI and going counterclockwise, the rule goes like this: If the terminal side of the angle is in the quadrant with letter.

# Domain The domain is all the values of θ that # Unit circle definition For this definition θ is any angle. Trig Cheat Sheet Definition of the Trig Functions