| 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=60 is greater than zero. That means that there are two solutions:
  . 
 
  
  
 Quadratic expression
  can be factored: 
  Again, the answer is: 2.77459666924148, 1.22540333075852.
Here's your graph:
 
  |