What did I do wrong with this?
f(x)= -x^2+4x+2
I divide 4 in half which is 2 and then double it which is 4.
Add +4
-x^2+4x+2+4
(-x+2)(-x+2) +6
(-x+2)^2 +6
the book says the vertex is at (2,6)
shouldn't it be opposite the sign within the parenthesis? which would be -2 or did i mess something up?
thx if you can help
2007-03-10 10:57:20 · 3 answers · asked by Boo Radley 4 in Science & Mathematics ➔ Mathematics
f(x) = -1(x^2 - 4x ) + 2
.......= -1 (x^2 - 4x + 4) + 2 + 4
....... = -1 (x - 2)^2 + 6
V = (2, 6)
2007-03-10 11:32:01 · answer #1 · answered by richardwptljc 6 · 0⤊ 0⤋
x a root of eqn => x^2 - 4x -2 = 0
=> (x - 2)^2 - 6 = 0
=> x = sqrt (6) + 2
2007-03-10 11:11:55 · answer #2 · answered by Dulcy L 1 · 0⤊ 0⤋
negative times negative is positive
common mistake! i do it all the time!
2007-03-10 11:07:15 · answer #3 · answered by o_0 2 · 0⤊ 0⤋