How do you solve csc^2x-2=0 and find all solutions in the interval [0,2pi)?

1 Answer
Apr 4, 2017

pi/4; (3pi)/4; (5pi)/4; (7pi)/4

Explanation:

1/(sin^2 x) = 2
sin^2 x = 1/2
sin x = +- 1/(sqrt2) = +- sqrt2/2
Trig table and unit circle gives 4 solutions:
a. sin x = sqrt2/2 -->
x = pi/4 and x = (3pi)/4
b. sin x = - sqrt2/2
x = - pi/4, or x = (7pi)/4 (co-terminal), and
x = pi - (-pi/4) = pi + pi/4 = (5pi)/4