Answer
$\frac{\pi}{3},\frac{2\pi}{3},\frac{4\pi}{3},\frac{5\pi}{3}$
Work Step by Step
Step 1. $f(x)=0 \longrightarrow 4sin^2(x)-3=0 \longrightarrow sin(x)=\pm\frac{\sqrt 3}{2}$
Step 2. For $sin(x)=\frac{\sqrt 3}{2}$, we have $x=\frac{\pi}{3},\frac{2\pi}{3}$
Step 3. For $sin(x)=-\frac{\sqrt 3}{2}$, we have $x=\frac{4\pi}{3},\frac{5\pi}{3}$
