For the first expression, \(\frac{e^{-x}-e^{x}}{2}\), recognize that it simplifies to \(-\sinh x\) using the definition of the hyperbolic sine function: \(\sinh x = \frac{e^x - e^{-x}}{2}\).
For the second expression, \((\cosh x)^{2}-(\sinh x)^{2}\), use the definitions of hyperbolic cosine and sine: \(\cosh x = \frac{e^x + e^{-x}}{2}\) and \(\sinh x = \frac{e^x - e^{-x}}{2}\). Then apply the identity \((\cosh x)^2 - (\sinh x)^2 = 1\).
Step 1: Simplifying the First Expression
We start with the expression
\[
\frac{e^{-x} - e^{x}}{2}.
\]
Using the definition of the hyperbolic sine function, we know that
\[
\sinh x = \frac{e^{x} - e^{-x}}{2}.
\]
Thus, we can rewrite the expression as
\[
\frac{e^{-x} - e^{x}}{2} = -\sinh x.
\]
Step 2: Simplifying the Second Expression
Next, we consider the expression
\[
(\cosh x)^{2} - (\sinh x)^{2}.
\]
Using the definitions of hyperbolic functions, we have
\[
\cosh x = \frac{e^{x} + e^{-x}}{2} \quad \text{and} \quad \sinh x = \frac{e^{x} - e^{-x}}{2}.
\]