Originally Posted by

**mathAna1ys!5** I don't understand one part of these questions.

.. Express each value as a function of an anlge in Quadrant 1.

35. cos 562 degrees

37. sin (-792degrees)

39. sec (sec (-210)

like the example question, tan 315 degrees

tan 315 degrees=sin 315 degrees/cos 315 degrees

= -sin 45 degrees/cos 45 degrees

= -tan 45 degrees

ok, first of all, how do you know which case to use in the symmetry identities? There are four cases. The textbook does not explain very well. Please give me a better understanding.