x-intercepts & coordinates of vertex of y = (x+3)(x-5)

belle<3

New member
Joined
Aug 27, 2007
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17
State the x-intercepts of the graph of the equation. Then find the coordinates of the vertex. y = (x + 3)(x - 5)

Okay so what I know is that the x-intercept means when y=0. and vice versa. So does that mean that the x-intercepts are x= -3 and x= 5? If that's so (and if that is not so) how do I find the coordinates of the vertex?
 

Mrspi

Senior Member
Joined
Dec 17, 2005
Messages
2,128
Re: x-intercepts & coordinates of the vertex?

belle<3 said:
State the x-intercepts of the graph of the equation. Then find the coordinates of the vertex. y = (x + 3)(x - 5)

Okay so what I know is that the x-intercept means when y=0. and vice versa. So does that mean that the x-intercepts are x= -3 and x= 5? If that's so (and if that is not so) how do I find the coordinates of the vertex?
It is true that the graph intersects the x-axis when x = -3, and when x = 5. The x-coordinate of the vertex is halfway between the x-intercepts.

Find the number that is halfway between -3 and 5. That's the x-coordinate of the vertex. To find the y-coordinate of the vertex, substitute your value of x into the original equation.

I hope this helps you.
 
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