## Haleyy_Bugg 2 years ago The graph of which quadratic equation is shown below? y = x^2 + 2x − 8 y = x^2 − 2x − 8 y = −x^2 − 2x + 8 y = −x^2 − 4x − 8

1. Haleyy_Bugg

2. Haleyy_Bugg

@Notamathgenius

3. Notamathgenius

Hmm not sure D:

4. MathCurious

Does the graph of x^2 open up or down? How about -x^2? :)

5. cwrw238

as its -x^2 it will be open downwards like C and D

6. MathCurious

f(x) + C will affect the position on the y axis. Take this fact into consideration.

7. cwrw238

yup the intercept on y-axis is when x = 0

8. MathCurious

|dw:1368631726428:dw| can you find the x -intercepts?

9. MathCurious

you should know the answer from this

10. Haleyy_Bugg

I dont

11. MathCurious

ok, set everything I drew above to zero, that is like saying: When is Y zero? When Y is zero it touches the x-axis

12. MathCurious

it is zero when x = 2 and when x = -4

13. Haleyy_Bugg

14. MathCurious

So then the answer is y = −x^2 − 2x + 8 I factored out the negative sign above.

15. MathCurious

look at your graph, it's consistent with this

16. MathCurious

Make sense? :)

17. MathCurious

lol, just looking for someone to do your homework without effort, eh?

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