(Solved): a) Convert the angle \( 150^{\circ} \) to exact radians. b) Find two angles in radians, one positiv ...

a) Convert the angle \( 150^{\circ} \) to exact radians. b) Find two angles in radians, one positive and one negative, that are coterminal to the angle in part "a." c) Use the methods of Section \( 1.3 \) to find the exact value of \( \cos \left(150^{\circ}\right) \). Be sure to graph the angle in standard position, find the reference angle, and show how you use that to determine the cosine value. d) Use the methods of Section \( 1.4 \) to find the exact value of \( \cos \left(150^{\circ}\right) \). Be sure to show the angle's location on the Unit Circle and the particular ordered pair \( (x, y) \) on the unit circle that enables you to determine the cosine value. e) Graph three periods of the function \( y=\cos x \) and then identify on the graph the value of \( y=\cos \left(150^{\circ}\right) \). Be sure to label the vertical and horizontcl axes with key values in each period. Put a big star or other identifiable symbol where the value of \( y=\cos \left(150^{\circ}\right) \) is located.