Tan(90 θ) = cotθ;2, π, etc) b) Use the 2 special triangles (and reference angles) for all other angles That applies to any angle (positive or negative) which is a multiple of π 6, π 4,or π 3 c) Don't memorize reciprocal values To find csc π 6, just take sin π 6 and invert PRACTICE PROBLEM for Topic 6 – Exact Values of sinθ, cosθ, and tanθ See next page −→ Math 109 T6Exact Values ofCot 2 θ 1 = cosec 2 θ Lets look at the complementary angles in trigonometric ratios, sin(90 θ) = cosθ;
Trigonometry Angles Pi 4 From Wolfram Mathworld