SOLUTION: find the x-intercepts of the parabola with vertex (-3,16) and y-intercept (0,-20). Write your answer in this form: (x1,y1),(x2,y2). If necessary, round to the nearest hundredth

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Question 1085857: find the x-intercepts of the parabola with vertex (-3,16) and y-intercept (0,-20). Write your answer in this form: (x1,y1),(x2,y2). If necessary, round to the nearest hundredth
Found 2 solutions by josmiceli, MathTherapy:
Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website!
The general formula is:

The formula for the vertex is:

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You are given 2 points:
( -3,16 )
( 0, -20 )
Plug these values into the general formula
(-3,16)

(0,-20)

------------
Now the equation is:

Al;so:

( given )

So, now I have:

also
( given )

and

so, the equation is:

----------------------------
Find the roots:

----------------
The other root is at:

The x-intercepts are:
( -5,0 ) and ( -1,0 )
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Here's the plot:

check the math and get an other opinion if needed

Answer by MathTherapy(10557) (Show Source):
You can put this solution on YOUR website!

find the x-intercepts of the parabola with vertex (-3,16) and y-intercept (0,-20). Write your answer in this form: (x1,y1),(x2,y2). If necessary, round to the nearest hundredth

<===== Vertex form of a parabolic equation ------- Substituting (0, - 20) for (x, y) and (- 3, 16) for (h, k) - 20 = 9a + 16 - 20 - 16 = 9a - 36 = 9a <===== Vertex form of a parabolic equation ------- Substituting 0 for y, - 4 for a, and (- 3, 16) for (h, k) (x + 5)(x + 1) = 0 x = - 5 OR x = - 1