What is the focus of the parabola x^2 = -12y?
Answer and explanation
Correct answer: A. (0, -3)
- Step 1: Standard form opening downward: x^2 = -4ay. Step 2. 4a = 12 => a = 3. Step 3. Focus is located at (0, -a) = (0, -3). Answer: (0, -3). Why not the others: (0, 3) is for x^2 = +12y; (-3, 0) is for y^2 = -12x.
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