Choose the equation below that corresponds to the graph shown:

y = 2x^2 + 8x − 3
y = −2x^2 + 8x − 3
y = 2x^2 − 8x − 3
y = −2x^2 − 8x − 3

Question

Choose the equation below that corresponds to the graph shown:

y = 2x^2 + 8x − 3
y = −2x^2 + 8x − 3
y = 2x^2 − 8x − 3
y = −2x^2 − 8x − 3

anonymous · Answer

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anonymous · Answer

if a > 0, the parabola will open upwards
if a < 0, the parabola will open downwards

the x value of the vertex is x = -b/2a

given this, you should be able to determine which is the equation.
locate the x value of the vertex and compare
also, does the graph open up or down?

anonymous · Answer

Thank you for the information :) and it opens downwards

anonymous · Answer

@pjpilot326 Thank you so much I was able to figure it out ^-^ there's your medal and thanks again for all the help and just to make sure the answer is D right?

anonymous · Answer

that's right so you only have to look at the x value of the vertex and compare based on -b/2a for the 2 equations that open down

anonymous · Answer

Thank you ^-^

anonymous · Answer

yep, you got it!!! and you're welcome!!!