SOLUTION: what is the x- intercept of this parabola y=-x^2+2x+3

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Question 170708: what is the x- intercept of this parabola y=-x^2+2x+3
Found 2 solutions by Mathtut, jojo14344:
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
y=-%28x%5E2-2x-3%29
:
y=-%28x-3%29%28x%2B1%29
:
y=%283-x%29%28x%2B1%29 x intercepts when they exist are found when y=0
set 3-x=0 and x+1=0.....x interceptssystem%28x=3%2Cx=-1%29

Answer by jojo14344(1512) About Me  (Show Source):
You can put this solution on YOUR website!
y=-x%5E2%2B2x%2B3 ----> x%5E2-2x-3=0
We solve th eqn by Quadratic Formula:x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
where--->system%28a=1%2Cb=-2%2Cc=-3%29
x=%28-%28-2%29%2B-sqrt%28-2%5E2-4%2A1%2A-3%29%29%2F%282%2A1%29
x=%282%2B-sqrt%284%2B12%29%29%2F2=%282%2B-sqrt%2816%29%29%2F2=%282%2B-4%29%2F2
2 values:
x=%282%2B4%29%2F2=6%2F2=highlight%283%29
x=%282-4%29%2F2=-2%2F2=highlight%28-1%29
X-intercepts,(-1,0) & (3,0)
See graph
drawing%28300%2C300%2C-7%2C7%2C-7%2C7%2Cgrid%281%29%2Cgraph%28300%2C300%2C-7%2C7%2C-7%2C7%2C-x%5E2%2B2x%2B3%29%2Cblue%28circle%283%2C0%2C.15%29%29%2Cblue%28circle%28-1%2C0%2C.15%29%29%29
.
Thank you,
Jojo