How to find a focus of a parabola with the vertex (-3,1) and the directrix: x=-8 given? Help please!
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Vertex (- 3, 1):
h = - 3
k = 1
Directrix: x = - 8
Since the directrix is a function of x, the parabola is parallel to the x-axis.
Distance from focus to vertex = p
p = h - x
p = - 3 - (- 8)]
p = - 3 + 8)
p = 5
Since p is positive, the focus is to the right of the vertex ( + x direction).
Focus (h + p, k)
Focus (- 3 + 5, 1)
Focus (2, 1)
¯¯¯¯¯¯¯¯¯¯¯
h = - 3
k = 1
Directrix: x = - 8
Since the directrix is a function of x, the parabola is parallel to the x-axis.
Distance from focus to vertex = p
p = h - x
p = - 3 - (- 8)]
p = - 3 + 8)
p = 5
Since p is positive, the focus is to the right of the vertex ( + x direction).
Focus (h + p, k)
Focus (- 3 + 5, 1)
Focus (2, 1)
¯¯¯¯¯¯¯¯¯¯¯