Answer
All real numbers $x$ such that $x \ne \pi /6 + 2\pi k, 5\pi/6 + 2\pi k$ where $k$ is an integer
Work Step by Step
The denominator must not equal 0:
$\sin x - 1/2 \ne 0$
$\sin x \ne 1/2$
$x \ne \pi /6 + 2\pi k, 5\pi/6 + 2\pi k$ where $k$ is an integer
