Conics p.d help (1 Viewer)

[cutemouse]

Hello,

I'm using perp. dist. for the question below but it isn't working out =(... Could someone please help me?

The tangent at P is xsec@/a - ytan@/b -1 =0. Show that if the tangent at P is also a tangent the circle with centre (ae,0) and radius sqrt(e²+1)*a, then show sec@=-e

Thanks

EDIT: Uploaded question as image.