Answer
$2.5$
Work Step by Step
Substitute $\frac{\pi}{6}$ to $x$ to obtain:
$3-\sin{x}= 3-\sin{(\frac{\pi}{6})}$
$\dfrac{\pi}{6}$ is a special angle whose sine value is $\frac{1}{2}$.
Thus, when $x=\frac{\pi}{6}$,
$3-\sin{x} = 3- \frac{1}{2}=\frac{6}{2} -\frac{1}{2} = \frac{5}{2} = 2.5$
