
Steve C. answered 06/10/15
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Steve C. Math & Chemistry Tutoring
Rewrite the equation in conic form: y2 - 8x + 10y + 9 = 0. --> 8x - 9 = y2 + 10y = y2 + 10y + 25 - 25. --> 8x + 16 = (y + 5)2 --> 8(x + 2) = (y + 5)2
4p = 8 --> p = 2
Vertex is (-2, -5)
Focus is (-2+2, -5) --> (0, -5)
Directrix is x = -2-2 --> x = -4