SOLUTION: Solve the quadratic equation formula.

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Question 305451: Solve the quadratic equation formula.
Found 2 solutions by edjones, richwmiller:
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
x^2-2x-13=0
x^2-2x =13
x^2-2x+1=14 completing the square.
(x-1)^2=14
x-1=+-sqrt(14)
x=1+sqrt(14), x=1-sqrt(14)
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Ed
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-2x%2B-13+=+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=%28-2%29%5E2-4%2A1%2A-13=56.

Discriminant d=56 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--2%2B-sqrt%28+56+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-2%29%2Bsqrt%28+56+%29%29%2F2%5C1+=+4.74165738677394
x%5B2%5D+=+%28-%28-2%29-sqrt%28+56+%29%29%2F2%5C1+=+-2.74165738677394

Quadratic expression 1x%5E2%2B-2x%2B-13 can be factored:
1x%5E2%2B-2x%2B-13+=+1%28x-4.74165738677394%29%2A%28x--2.74165738677394%29
Again, the answer is: 4.74165738677394, -2.74165738677394. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-2%2Ax%2B-13+%29

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
Instructions on how to write squared or second power are on the submit page. Read it and try again.