Hyperboloid of one sheet
a. Find a parametrization for the hyperboloid of one sheet $x^{2}+y^{2}-z^{2}=1$ in terms of the angle $\theta$ associated with the circle $x^{2}+y^{2}=r^{2}$ and the hyperbolic parameter $u$ associated with the hyperbolic function $r^{2}-z^{2}=1 .$ (See Section $7.8,$ Exercise $84 . . )$
b. Generalize the result in part (a) to the hyperboloid $\left(x^{2} / a^{2}\right)+\left(y^{2} / b^{2}\right)-\left(z^{2} / c^{2}\right)=1$