SOLUTION: Quadratic Equations Find the x-intercepts of each parabols. c) y=x^2-4x+4 d) y=4x^2-12x+9 Thank you very much pleaseeeeeeeeeeee

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Question 178086: Quadratic Equations
Find the x-intercepts of each parabols.
c) y=x^2-4x+4
d) y=4x^2-12x+9
Thank you very much pleaseeeeeeeeeeee

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Quadratic Equations
Find the x-intercepts of each parabola.
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The x-intercepts are the points that y = 0, so set the function = 0 and solve.
c) y=x^2-4x+4
x^2 - 4x + 4 = 0
(x-2)*(x-2) = 0
Only one intercept, at (2,0)
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-4x%2B4+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-4%29%5E2-4%2A1%2A4=0.

Discriminant d=0 is zero! That means that there is only one solution: x+=+%28-%28-4%29%29%2F2%5C1.
Expression can be factored: 1x%5E2%2B-4x%2B4+=+%28x-2%29%2A%28x-2%29

Again, the answer is: 2, 2. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-4%2Ax%2B4+%29

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d) y=4x^2-12x+9
4x^2 - 12x + 9 = 0
(2x-3)*(2x-3) = 0
Same here, one point where the parabola is tangent to the x-axis.
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 4x%5E2%2B-12x%2B9+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-12%29%5E2-4%2A4%2A9=0.

Discriminant d=0 is zero! That means that there is only one solution: x+=+%28-%28-12%29%29%2F2%5C4.
Expression can be factored: 4x%5E2%2B-12x%2B9+=+%28x-1.5%29%2A%28x-1.5%29

Again, the answer is: 1.5, 1.5. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+4%2Ax%5E2%2B-12%2Ax%2B9+%29