SOLUTION: can someone help y=2x^2-4x-1 the vertex (1,-3) y-intercept (0,-1) the x-intercepts enter the x-intercept with the smaller x value ( , 0 )?? enter the x-intercept with the

Algebra ->  Graphs -> SOLUTION: can someone help y=2x^2-4x-1 the vertex (1,-3) y-intercept (0,-1) the x-intercepts enter the x-intercept with the smaller x value ( , 0 )?? enter the x-intercept with the      Log On


   



Question 198634: can someone help
y=2x^2-4x-1
the vertex (1,-3)
y-intercept (0,-1)
the x-intercepts
enter the x-intercept with the smaller x value
( , 0 )??
enter the x-intercept with the larger x value
(2.224,0)
can not figure out the the first part of the smaller x value question
can someone help please

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
2x^2-4x-1=0
x^2-2x-(1/2)=0 divide each side by 2
x^2-2x=.5
x^2-2x+1=1.5 completing the square.
(x-1)^2=1.5
x-1=+-sqrt(1.5)
x=1+-sqrt(1.5)
x=1-sqrt(1.5)= -0.225
x=1+sqrt(1.5)= 2.225
.
It is more exact and less of a mess with decimal points and rounding if you keep it 1+-sqrt(1.5)
.
Ed
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graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C2x%5E2-4x-1%29