SOLUTION: the square of a number minus four times the number equals one. What is the number?

Question 1030341: the square of a number minus four times the number equals one. What is the number?
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
n^2 - 4n = 1
--------
n^2 - 4n - 1 = 0

Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)

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: 4.23606797749979, -0.23606797749979. Here's your graph:

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