Equation of the parabola in factored form

[adrianogaleno]

I spent the whole day in this problem and couldn't find the solution. We can easily identify the x-intercepts (-5 and -1), but I was not able to figure out the vertex (-3, ???).
Thank you

Problem - Determine the equation of the parabola shown below in factored form. Convert answer to both standard form and vertex form.

 

[Dr.Peterson]

I spent the whole day in this problem and couldn't find the solution. We can easily identify the x-intercepts (-5 and -1), but I was not able to figure out the vertex (-3, ???).
Thank you

Problem - Determine the equation of the parabola shown below in factored form. Convert answer to both standard form and vertex form.

It looks to me like it's about 3.5. Don't you agree? That's the best we can do; so write an equation based on that, and see if it looks right when you graph it.

In case you're also asking how to write the equation, you can just call the coefficient a, plug in x=3, and solve for a. (It won't be a particularly nice number.)

(By the way, in the future, please show some version of the actual work, rather than just a general description of it; that often helps us get to the point quicker.)

 

[Steven G]

Go to x=-3 on the x-axis. Go straight down and up from that point until you hit the graph. While looking up and down do not move your eyes to the left or right--just up and down. When you reach a point on the graph look (left or right) to the y-axis and read off the value. It looks to me (and Dr Peterson) as 3.5