Question 1011138: How do I identify the focus, directrix and axis of symmetry when y= -1/12x^2? Found 2 solutions by MathLover1, It is costly:Answer by MathLover1(20850) (Show Source):
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we can see that the vertex will be at (,)=(,)
The standard form of a parabola (in this case upside down parabola) with a vertical axis of symmetry is
, where is the directed distance between the vertex and focus (and also between the vertex and directrix)
since and , we have
since you have , then
focus | (,)=(, )
p is the directed distance between the vertex and directrix, directrix will be units above x-axis :