Finding a vertex

H

Haylea

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Jan 11, 2021
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So I need to find the vertex for these two graphs but I am not sure how. I have the first part of both vertex which I will list below (blanks are what I can't figure out), I just don't understand how to get the Y value. I have also included the question in my screenshot, so if I do not need to find the vertex please inform me of that. Thanks!
7. (-1.5,__)
8. (-4.5,__)
Also, I need help figuring out their intercept forms.
Screenshot 2021-01-11 at 3.47.21 PM.png
 
Last edited:
It's ALWAYS the middle of the zeros. x = 2, x = -5, find the x-coordinate by averaging the two (2 - 5)/ 2 = -3/5 = -1.5. Confirmed by the given information.

Also, find the equation using the factors related to the zeros. y = (x-2)(x+5) -- You're almost done.
 
The equation of your curve is y=A(x-2)(x+5). Find the value for A and then plug in the x-value they gave you.
 
Haylea said:
… I need help figuring out their intercept forms.
Click to expand...
Hi Haylea. Jomo has shown you the intercept form, for the first exercise. It's the factored form that shows the x-intercepts and leading coefficient A. (Note: When A=1, we don't write it).

We use the coordinates of the third point, to find the value of A. In the first exercise, the third point tells us that y=8 when x=-1.

If you'd like more help, please show what you tried. Thanks!

?
 
tkhunny said:
It's ALWAYS the middle of the zeros. x = 2, x = -5, find the x-coordinate by averaging the two (2 - 5)/ 2 = -3/5 = -1.5. Confirmed by the given information.

Also, find the equation using the factors related to the zeros. y = (x-2)(x+5) -- You're almost done.
Click to expand...
Thank you for the help!
 
Otis said:
Hi Haylea. Jomo has shown you the intercept form, for the first exercise. It's the factored form that shows the x-intercepts and leading coefficient A. (Note: When A=1, we don't write it).

We use the coordinates of the third point, to find the value of A. In the first exercise, the third point tells us that y=8 when x=-1.

If you'd like more help, please show what you tried. Thanks!

?
Click to expand...
Thank you! I'll reply again later if I require more assistance :)
 
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