What is the right choice for question 37) ? http://postimg.org/image/9ikm61h8f/

Expert Answers
baxthum8 eNotes educator| Certified Educator

The CAST rule applies to the positive values of functions in the xy-plane.  C starts in quadrant 4 therefore only the cosine is positive in quadrant IV.  AST moves in the counterclockwise direction for each quadrant. A is in quadrant I which indicates ALL (sine,cosine, and tangent) are positive in quadrant I, S is quadrant II which indicates only the sine is positive in quadrant II, and T indicating tangent is positive in quadrant III.

Therefore the CAST rule applies to choice: "d"