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@campbell_st
for this type of question I always use the general form \[(x - h)^2 = 4a(y - k)\] the vertex is (h, k) and the focal length is a so start by finding the focal length... the distance between the directrx and focus on the line of symmetry is souble the focal length so how far between y = -2 and y = 6...?
4?
No 8
My bad, I did it wrong
can you just check the directrixx is y = -2 and focus is (2, 6)
great, 8 is correct... so to find the value of a, just ahlve the answer you has for the distance between the focus and directrix...
thedirectrix is below the focus... so the parabola is concave up... and the vertex is a units below the focus on the line of symmetry x = 2 so the vertex is (2, 6 - a)
Kinda confused, do I need to subtract something?
ok... you need to find a, based on the information 2a = 8 the disatnce between y = -2 and y = 6 so what is the value of a..?
4
great the vertexx of the parabola is a units below the focus on the line x = 2 so the vertex is (2, 6 - a) using your value of a, what is the vertex..?
|dw:1416960918629:dw|If I draw a simple plot of the info I know the parbola is concave up
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