SOLUTION: Can someone help me with the following problemwith finding zeroes? f(x)=x^2-5x+1

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Question 275254: Can someone help me with the following problemwith finding zeroes?
f(x)=x^2-5x+1
Answer by Greenfinch(383) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 - 5x + 1 = 0
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-5x%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=%28-5%29%5E2-4%2A1%2A1=21.

Discriminant d=21 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--5%2B-sqrt%28+21+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-5%29%2Bsqrt%28+21+%29%29%2F2%5C1+=+4.79128784747792
x%5B2%5D+=+%28-%28-5%29-sqrt%28+21+%29%29%2F2%5C1+=+0.20871215252208

Quadratic expression 1x%5E2%2B-5x%2B1 can be factored:
1x%5E2%2B-5x%2B1+=+1%28x-4.79128784747792%29%2A%28x-0.20871215252208%29
Again, the answer is: 4.79128784747792, 0.20871215252208. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-5%2Ax%2B1+%29