Question

Identify the vertex for the graph of y = −2x2 − 12x + 1.

Answer 1

formula to find x-coordinate of the vertex \[\rm x=\frac{-b}{2a}\]
and then substitute x for its value into the equation to find y-coordiante

Answer 2

y=Ax^2+Bx+C
quadratic equation where
a=leading coefficient
b=middle term(coefficient of x term)
c=constant

Answer 3

(−3, 19)
(−3, 55)
(3, −53)
(3, −47)

Answer 4

those are the options

Answer 5

okay.good now plugin a b values into the formula to find x-coordinate

Answer 6

Is it C?

Answer 7

how did you get that ? post ur work

Answer 8

I did it on my notebook its to long, it is correct right?

Answer 9

take a pic post it here
it should't be that long
what's a value what is b ?

Answer 10

You can check your work pretty easily by evaluating two more points.

You think that \((3,-53)\) is the vertex. If it is the vertex, then the points at \(x=3+1=4\) and \(x=3-1=2\) ought to have the same \(y\) value, because the parabola is symmetrical about a line through the vertex. Plug in those two values of \(x\) in the original formula and see if you get identical values for \(y\). If you do, you are correct. If you do not, you are not.

Answer 11

Hint: I strongly suggest you use my test :-)