2006-07-31 07:14:13 · 5 answers · asked by Brandon ツ 3 in Science & Mathematics ➔ Mathematics
it's (3,20)
if you just do a chart of points:
(x,y)
(2,17)
(3,20)
(4,17)
2006-07-31 07:22:55 · answer #1 · answered by Caroline I 2 · 1⤊ 1⤋
24
2006-07-31 14:27:34 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Caroline is correct but the proper way to solve this problem is to take the first derivative and set that equal to zero and then solve for x.
Therefore
y' = -6x +18
0 = -6x + 18
6x = 18
x = 3
Plug x = 3 back into original equation and you have y = 20.
2006-07-31 15:47:16 · answer #3 · answered by Will 4 · 0⤊ 0⤋
y = -3x^2 + 18x - 7
x = (-b)/(2a)
x = (-18)/(2(-3))
x = (-18)/(-6)
x = 3
y = -3(3)^2 + 18(3) - 7
y = -3(9) + 54 - 7
y = -27 + 54 - 7
y = 27 - 7
y = 20
Vertex : (3,20)
2006-07-31 17:38:30 · answer #4 · answered by Sherman81 6 · 0⤊ 0⤋
when f(x) = ax^2 + bx + c, the vertex is
(-b/2a, (4ac-b^2)/4a) ...
2006-07-31 17:03:35 · answer #5 · answered by shamu 2 · 0⤊ 0⤋