directrix

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(y-7)^2 = 8(x-6)

directrix x = _____

isnt the directrix just -p?

4p=8
p=2

so shouldnt the directrix be -2? but -2 doesnt work

[AKG]

What the heck is p? Why is 4p = 8, and what does that even mean? Do you know what you're supposed to do? Do you know what the directrix is? Do you know what type of conic section you're dealing with? Before this post, I didn't know what a directrix was (although I had a vague idea). I looked it up on mathworld, and managed to solve this problem easily, so where exactly is it that you're having trouble? I can only assume that you don't know what it is you're supposed to do, because it's a very simple problem.