SOLUTION: What is the equation of a parabola with the directrix of x=7 that has its vertex at the origin

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Question 966743: What is the equation of a parabola with the directrix of x=7 that has its vertex at the origin
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
The focus is (0,0), and the meaning of the directrix is (7,y). Use the definition of a parabola with the Distance Formula.

sqrt%28%28x-7%29%5E2%2B%28y-y%29%5E2%29=sqrt%28%28x-0%29%5E2%2B%28y-0%29%5E2%29

Simplify that.