quadratic function?

0 ⤊

f(x)= a[(x+4)^2]-9

what's a if we know f(0)= -4?

2006-10-27 17:06:08 · 4 answers · asked by levine 2 in Science & Mathematics ➔ Mathematics

Suppose f(x)= a[(x+4)^2]-9.

If f(0) = -4, then -4 = a[(0 + 4)^2] - 9 = 16a - 9. So, we have,
16a = -4 + 9
16a = 5
a = 5/16.

2006-10-27 17:13:07 · answer #1 · answered by rei24 2 · 0⤊ 0⤋

Plug in x=0 and you get a[(0+4)^2] - 9 = 16a - 9. Setting this equal to -4 gives 16a = 5, so a=5/16.

2006-10-28 00:10:22 · answer #2 · answered by James L 5 · 0⤊ 0⤋

a= 5/16

2006-10-28 00:30:14 · answer #3 · answered by arleth m 2 · 0⤊ 0⤋

first off it would be f(x)=-4 and no it doesnt come out right when you plug-in the -4 for x

2006-10-28 00:15:04 · answer #4 · answered by slipperysizzler 2 · 0⤊ 0⤋