The graph of which quadratic equation is shown below?

y = −x2 + 6x + 8

y = −x2 − 6x + 8

y = x2 + 6x + 8

y = x2 − 6x + 8

Question

The graph of which quadratic equation is shown below?



 y = −x2 + 6x + 8

 y = −x2 − 6x + 8

 y = x2 + 6x + 8

 y = x2 − 6x + 8

anonymous · Answer

attachment

luigi0210 · Answer

well the equation is opening upward, so we know from that that it has a positive x^2 value

luigi0210 · Answer

so that eliminates half the choices

anonymous · Answer

so would it  be c?

luigi0210 · Answer

according to the graph, there is a ponit, (-3, -1) so what i would do is plug that into the equation to see which one is true

jhannybean · Answer

the parabola follows teh equation $$ \large y = a(x –\color{red} h)^2 + \color{red}k$$ and your vertex $$\large v=\color{red}{(-3,-1)}$$

luigi0210 · Answer

$$-1=x^2+6x+8$$
$$-1=(-3)^2+6(-3)+8$$
$$-1=9-18+8$$
$$-1=-1$$

luigi0210 · Answer

$$-1=(-3)^2-6(-3)+8$$
$$-1=9+18+8$$
$$-1\neq 35$$

luigi0210 · Answer

Does it make sence @sumsumjoe

luigi0210 · Answer

*sense

jhannybean · Answer

after plugging in the points of your vertex, expand the equation. $$\large y=(x+3)^2+1$$$$\large y=(x+3)^2-1$$$$\large y=x^2+6x+9-1$$$$\large y=x^2+6x+8$$

luigi0210 · Answer

And watch out for this girl :P
She's great at explaining

luigi0210 · Answer

You're welcome joe :l

jhannybean · Answer

xD

luigi0210 · Answer

Ans thank you Miss Jhan for reminding me about the vertex

jhannybean · Answer

No problem :)