Answer
$sinh~2x = 2~sinh~x~cosh~x$
Work Step by Step
$sinh~2x = \frac{e^{2x}-e^{-2x}}{2}$
$sinh~2x = \frac{(e^{x}-e^{-x})(e^x+e^{-x})}{2}$
$sinh~2x = \frac{2(e^{x}-e^{-x})(e^x+e^{-x})}{4}$
$sinh~2x = 2~\frac{e^{x}-e^{-x}}{2}\cdot \frac{e^x+e^{-x}}{2}$
$sinh~2x = 2~sinh~x~cosh~x$
