Question 743917: Find the vertx, the directrix, and the focus.
(x-4)^2 = 4(y+1)
Answer by crazylogms(2)   (Show Source):
You can put this solution on YOUR website! Given (x-4)^2 = 4(y+1) ------------------> (1)
Comparing to (x-h)^2 = 4a(y-k) ------------------> (2)
(h,k) = (4,-1) ----------> Vertex
From (1) & (2),
4a = 4 ,[ a=1 ]
Equation of directrix y-k=-a, y+1=-1, y=-2 --------> Equation of directrix
Vertex of Parabola (x-h=0, y-k=a)
x=h , y=a+k
x=4 , y=0
(4,0) ---------------------------------> Vertex of Parabola.
Cheers
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