I found $\displaystyle y = \sqrt{\frac{b^2x^2}{a^2} - b^2}$

then Area = $\displaystyle b \int \sqrt{\frac{x^2}{a^2} - 1}dx$ with upper limit c and lower a.

I then let x = acosht, is this correct?

then did the method of substitution.

then what do I do? My end answer looks very weird...so i just want to make sure.