Find the solutions to the following equations in the interval [0,2 ].

(c) sin2x=−23 .

Note.sin2xmeans sin(2x) and not (sin2)x.

Hint.The anglexbelongs to the interval [0,2 ] if and only if the angle 2xbelongs 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..