Day 3 – Sine, Cosine and Tangent of Angles from 0 – 360 (CAST) CAST Rule Recall: Standard position - Tells us the ______________ of each trig ratio in each of the ______ Draw the following angles in standard position: ________________________. Reference Angles: The reference angle is the _______________ (less than 90°) angle Why are Reference Angle Important? between the terminal arm and the ___________________. Ex. 2 Find the exact trig ratio of the following: ** a) sin 135o Ex. 1 What is the reference angle of the following angles in standard position? b) tan( 210o ) c) cos 300 o d) tan( 150 ) o Ex. 3: Find the exact values of sin , cos , and tan given P(3, -2) lies on the terminal arm. b) sin B 5 , quadrant III 11 4 c) tan C , quadrant IV 3 12 and angle A is in quadrant I. 13 a) Draw a diagram. Ex. 5: sin A b) Determine exact values of cosA and sinA. Ex. 4: One of the primary trig ratios is given, as well as the quadrant in which the terminal arm lies. Determine the other two primary trig ratios. Give exact answers. 3 a) cos A , quadrant I 5 c) How would the answers in part a) and b) change if the quadrant of angle A wasn’t given?