Question #3837a

1 Answer
Dec 5, 2017

x = pi/2 + 2kpi
x = (3pi)/2 + 2kpi
x = +- pi/3 + 2kpi

Explanation:

#48sin^2 x = 48 - 24cos x#
Replace #sin^2 x# by #1 - cos^2 x#:
#48 - 48cos^2 x = 48 - 24cos x#
#48 cos^2 x - 24 cos x = 0#
#24cos x(2cos x - 1) = 0#
Either factor should be zero.
a. cos x = 0. Unit circle gives 2 solutions
#x = pi/2 + 2kpi#, and #x = (3pi)/2 + 2kpi#
b. 2cos x = -1 --># cos x = 1/2#
Trig table and unit circle give 2 solutions:
#x = +- pi/3 + 2kpi#