Date: Tue, 21 Jul 1998 20:13:20 -0600 (CST)
Subject: parabolas

Name: Danica

Who is asking: Student
Level: All

how do you find the focus, vertex, and directrix of 4x-y^2-2y-33=0

Hi Danica,
I think that you should begin by expressing the parabola in standard form. First write


Now add one to both sides and the expression becomes


This expression can be written as
Now you can find the focus, vertex, and directrix in terms of s and t and then express them in terms of x any y using the fact that t = y+1 and s = x-8.


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