Answer
See the explanation below.
Work Step by Step
We use the trigonometric identity: $2\sin x\cos x=\sin 2x$.
Now, the left side can be written as:
$\begin{align}
& \sin 2x\sec x=2\sin x\cos x\times \frac{1}{\cos x} \\
& =2\sin x
\end{align}$
Thus, the left side is equal to $2\sin x$.
