Question

Choose the equation below that corresponds to the graph shown.

graph of a u-shaped figure opening downward with a maximum point of (−2, 5)

y = 2x2 + 8x − 3

y = −2x2 + 8x − 3

y = 2x2 − 8x − 3

y = −2x2 − 8x − 3

Answer 1

vertex is at \((-2,5)\) so you might try
\[y=2(x+2)^2-5\]

Answer 2

all your options have a leading coefficient of 2, so you know it has to look like that one

Answer 3

multiply out and see what you get
if you still need help let me know

Answer 4

i got a

Answer 5

yeah and i am an idiot, sorry for confusing you
the parabola opens DOWN not up, so it is
\[y=-2(x+2)^2+5\]

Answer 6

or
\[y=-2x^2-8x-3\]

Answer 7

so d?

Answer 8

yes

Answer 9

can you help me with this?



Find the vertex of the quadratic equation: y = 2x2 + 8x − 4.

(−2, 20)

(−2, −12)

(2, 20)

(−2, −28)

Answer 10

yes to find the vertex, the first coordinate is always \(-\frac{b}{2a}\) which in your case is \(-\frac{8}{2\times 2}=-2\)

Answer 11

the second coordinate is what you get when you replace \(x\) by \(-2\)

Answer 12

in this case you get
\[2\times (-2)^2+8\times -2-4=8-16-4=-8-4=-12\]

Answer 13

making your vertex \((-2,12)\)