SOLUTION: What is the standard form equation of a parabola with directrix x=-2 and focus (2,0)?

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Question 968922: What is the standard form equation of a parabola with directrix x=-2 and focus (2,0)?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

the standard form equation of a parabola with directrix x=-2 and focus (2,0):
Let p(x,+y) ba any point on the parabola.
By definition of parabola,p(x,+y) is equidistant from the focus and the directirx. Thus, we have
%28x-2%29%5E2+%2B+%28y-0%29%5E2+=+%28x-%28-2%29%29%5E2
%28y-0%29%5E2+=+%28x%2B2%29%5E2-%28x-2%29%5E2
y%5E2+=+%28x%5E2%2B4x%2B4%29-%28x%5E2-4x%2B4%29
y%5E2+=+x%5E2%2B4x%2B4-x%5E2%2B4x-4
y%5E2+=+cross%28x%5E2%29%2B4x%2Bcross%284%29-cross%28x%5E2%29%2B4x-cross%284%29
y%5E2+=+4x%2B4x
y%5E2+=+8x=> your answer