SOLUTION: 5x^2+18x+1=0

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Question 27472: 5x^2+18x+1=0
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Quadratic with a=5,b=18,c=1
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 5x%5E2%2B18x%2B1+=+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=%2818%29%5E2-4%2A5%2A1=304.

Discriminant d=304 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-18%2B-sqrt%28+304+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%2818%29%2Bsqrt%28+304+%29%29%2F2%5C5+=+-0.0564404225837304
x%5B2%5D+=+%28-%2818%29-sqrt%28+304+%29%29%2F2%5C5+=+-3.54355957741627

Quadratic expression 5x%5E2%2B18x%2B1 can be factored:
5x%5E2%2B18x%2B1+=+5%28x--0.0564404225837304%29%2A%28x--3.54355957741627%29
Again, the answer is: -0.0564404225837304, -3.54355957741627. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+5%2Ax%5E2%2B18%2Ax%2B1+%29

Cheers,
Stan H.