SOLUTION: How do I use this formula x=(-bą√(b^2-4ac))/2a and find out what a, b, and c are, then plug those numbers in and get x-intercepts? The equation to solve is y=x^2+4x-1

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Question 247661: How do I use this formula x=(-bą√(b^2-4ac))/2a and find out what a, b, and c are, then plug those numbers in and get x-intercepts? The equation to solve is
y=x^2+4x-1
Answer by oberobic(2304)   (Show Source): You can put this solution on YOUR website!
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=20 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 0.23606797749979, -4.23606797749979. Here's your graph:
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