Find the x-intercepts of the parabola with vertex (-5,80) and y-intercept (0,-45). write your answer in this form: (x1,,y2). if necessary, round to the nearest hundredth.

(-9, 0), (-1, 0)

In vertex form, the equation of the parabola is ...

... f(x) = a(x +5)^2 +80

Then f(0) = -45 = a(5)^2 +80

... a = -125/25 = -5

Since we want the x-intercepts, we want the solutions to ...

... -5(x +5)^2 +80 = 0

... (x +5)^2 -16 = 0 . . . . . divide by -5

... x + 5 = ±√16 . . . . . . . add 16 and take the square root

... x = -5 ± 4 . . . . . . . . . . subtract 5

... x ∈ {-9, -1}

So the coordinates of the x-intercepts are (-9, 0) and (-1, 0).

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify

i think the correct option is the second option.