find the directrix and the focus of parabola x2212y1Solution

find the directrix and the focus of parabola (x+2)^2=12(y+1)

Solution

given (x+2)^2=12(y+1)

camape with (x-h)^2 = 4a(y-k)

h=-2,k=-1, a = 3

This parabola is opening to the right.

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Vertex =(h,k) = (-2,-1)

focus =(h+a,k) = (-2+3 , -1) =(1,-1)

directrix y = -1