AQA Core 4 2.03b Converting from Parametric Equations to a Cartesian Equation p2

[e.hamilton]

I paused the video to try the question first. I saw (x-y)(x+y) would expand to x^2-y^2, so decided to square our (2t-1/t) and (2t+1/t) values and subtract one from the other. It got to the right answer, but your way is faster.

Thanks for all these videos, they're really helping me learn.

[samt]

So how would the Cartesian equation look like? How do you use k, -8, in the parametoc equations to form a Cartesian equation? Thanks