Find the solutions to the following equations in the interval [0,2 ].
(c) sin2x=−23 .
Note. sin2x means sin(2x) and not (sin2)x.
Hint. The angle x belongs to the interval [0,2 ] if and only if the angle 2x belongs to the interval [0,4 ]. So, how many solutions does the given equation have in the interval [0,2 ] ?
What is this asking? I got 4pi/3 and 5p/3 but it's obviously not right.
Also the title should obviously be sin 2x not cos..