Finding Parametric Equations for the right side of Hyperbola I have this equation $x^2-y^2=1$. 
I can understand that it is a Hyperbola. But my question is, how can I create/find a parametric equation for the right side of this hyperbola? It seems it doesn't work, using $\sin$ or $\cos$. 
Thanks

Whit $r(t)=(x(t), y(t)) = (\sec(t), \tan(t))$ get the right branch, with $t \in\,]-\pi/2,\; \pi/2[$ (you can try for example $]-1.4,1.4[$). For the left branch you can try $r(t+\pi)$,  $t \in\,]-\pi/2,\; \pi/2[$.
Best is  $r(t)=(x(t), y(t)) = (\pm\cosh(t), \sinh(t))$, one sign for each branch. And you can use any interval $[-s,s]$. For example $r(t) = (\cosh(t), \sinh(t)), \; t \in\, [-1,1]$ and $r(0)$ is the vertex of the branch
