Question

Can someone please help me with ASAP. I need to do this by tonight thx.

Which equation represents a parabola with focus (3,8)
A. y=1/4(x-3)^2-9
B. y= 4(x+3)^2-8
C. y=1/4(x-3)^2-10
D. 4(x+2)^2+7
also please don't be a bot or a person who says " I don't know" its not helpful

Answer 1

Answer: C

Explanation:

If a parabola is given by
`a(x - h)^2 + k`, the focus is at the point
`(h, k + 1/4a)`.

We know the focus is
`(3, 8)`, so it should look like
`a(x - 3)^2 + k`. We can cross off B and D.

Let's check if A works:
`8 = -9 + 1/(4 \cdot \frac 14) = -8`. Obviously this is false, so we can cross off A.

Thus it's C by process of elimination.