Answer
$c1$ no intersection
Work Step by Step
We are given the functions:
$y=\sin x$, $0\leq x<2\pi$
$y=c$
The range of the function $y=\sin x$ is $[-1,1]$. Therefore we have:
$c1\Rightarrow$ no intersection
For $x=\dfrac{\pi}{2}$, the function $y=\sin x$ has a maximum of 1, therefore we have:
$c=1\Rightarrow$ one intersection
For $x=\dfrac{3\pi}{2}$, the function $y=\sin x$ has a minimum of -1, therefore we have:
$c=-1\Rightarrow$ one intersection
For the rest of the values of $c$, we have:
$-1