6 The curve \(C\) has equation \(y=\frac{x^{2}+x-1}{x-1}\).
(a) Find the equations of the asymptotes of \(C\).

(b) Show that there is no point on \(C\) for which \(1<y<5\).

(c) Find the coordinates of the intersections of \(C\) with the axes, and sketch \(C\).

(d) Sketch the curve with equation \(y=\left|\frac{x^{2}+x-1}{x-1}\right|\).