Question

5. Evaluate each of the following using the unit circle:
(a)
cos 390°

Answer 1

Answer:

#sin 390 = sin (30 + 360) = sin 30 = 1/2#

#cos 390 = cos (30 + 360) = cos 30 = sqrt3/2#

#tan 390 = tan 30 = 1/sqrt3 = sqrt3/3#

#cot 390 = 1/(tan 30) = sqrt3/1#

#sec 390 = 1/cos 30 = 2/sqrt3#

#csc 390 = 1/(sin 30) = 2/1#