Question 687729
Please help me solve this problem:
The following equation defines a parabola. Without actually graphing, find the vertex and determine whether the graph opens upward or downward.
(x-4)^2=y+8
.
Vertex form of a parabola is:
y = a(x-h)^2 + k
where (h,k) is the vertex.
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your problem gives you:
(x-4)^2=y+8
(x-4)^2 - 8=y
or
(x-4)^2 + (-8)=y
.
so, from inspection the vertex is at
(4, -8)
and, it opens upwards (since the coefficient associated with the x^2 is positive)