Question #38271

1 Answer
Apr 8, 2017

pi/4

Explanation:

sin x - cos x = 0
Use trig identity:
sin x - cos x = sqrt2sin (x - pi/4)
sqrt2sin (x - pi/4) = 0
sin (x - pi/4) = 0
Unit circle gives 3 solutions:
a. (x - pi/4) = 0 --> x = pi/4
b. x - pi/4 = pi --> x = pi + pi/4 = (5pi)/4 (out of interval)
c. x - pi /4 = 2pi --> x = 2pi + pi/4 = (9pi)/4 = pi/4