A curve \(C\) has parametric equations
\(x=t+\frac{1}{t}\), \(y=t-\frac{1}{t}\)
Find a Cartesian equation of \(C\). Sketch \(C\), giving the coordinates of any points where \(C\) crosses the \(x\)- and \(y\)-axes and the equations of any asymptotes.
The point \(P\) on the curve has parameter \(p\). Show that the straight line, \(\ell \), with equation \(\left( {{p}^{2}}+1 \right)x-\left( {{p}^{2}}-1 \right)y=4p\) cuts the curve only at \(P\).[6]