Question #9318a

1 Answer
Dec 6, 2017

#pi/6, (5pi)/6#

Explanation:

Note that:
#sin^2 t + cos^2 (-t) = sin ^2 t + cos ^2 t = 1#, and
#cos (pi/2 - t) = sin t#
After transformation, we get:
2sin t = 1 -->
#sin t = 1/2#
Trig table and unit circle give -->
#t = pi/6# and #t = (5pi)/6#