Hi,
A =
let x be the width of the border
18 = (6-x)^2 = 36 - 12x +x^2
x^2 - 12x + 18 = 0
x = 1.75735931288072
Solved by pluggable solver: SOLVE quadratic equation with variable Quadratic equation (in our case ) has the following solutons:
For these solutions to exist, the discriminantshould not be a negative number.
First, we need to compute the discriminant: .
Discriminant d=72 is greater than zero. That means that there are two solutions:.
Quadratic expressioncan be factored:
Again, the answer is: 10.2426406871193, 1.75735931288072. Here's your graph: