Solution
= Solution
Expand the two squares using the exponential definitions:
$$
\boxed{\cosh^2x-\sinh^2x=\frac{(e^x+e^{-x})^2-(e^x-e^{-x})^2}{4}=1.}
$$
= Solution
Expand the two squares using the exponential definitions:
$$
\boxed{\cosh^2x-\sinh^2x=\frac{(e^x+e^{-x})^2-(e^x-e^{-x})^2}{4}=1.}
$$