alleryFind focus and directrix of parabola y² = -8x:
AFocus (0, -2)
BNo focus
CFocus (-2, 0), directrix x = 2 (opens left, a = -2)
DFocus (2, 0), directrix x = -2
Answer & Solution
Correct answer: C. Focus (-2, 0), directrix x = 2 (opens left, a = -2)
y² = -8x → 4a = -8 → a = -2. Vertex (0, 0), opens left. Focus (a, 0) = (-2, 0). Directrix x = -a = 2.
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