## Calculus: Early Transcendentals 8th Edition

Use the definition of hyperbolic sine. Then, find $\sinh{(-x)}$ and factor out a negative sign. $$sinh(x) = \frac{e^{x} - e^{-x}}{2}$$ sinh(-x) = $\frac{e^{-x} - e^{-(-x)}}{2}$ = $\frac{e^{-x} - e^{-x}}{2}$ = $\frac{-(e^{x} - e^{-x})}{2}$ = -sinh(x)