u^2-3u+1=0

Solution for u^2-3u+1=0 equation:

Simplifying
u2 + -3u + 1 = 0

Reorder the terms:
1 + -3u + u2 = 0

Solving
1 + -3u + u2 = 0

Solving for variable 'u'.

Begin completing the square.

Move the constant term to the right:

Add '-1' to each side of the equation.
1 + -3u + -1 + u2 = 0 + -1

Reorder the terms:
1 + -1 + -3u + u2 = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -3u + u2 = 0 + -1
-3u + u2 = 0 + -1

Combine like terms: 0 + -1 = -1
-3u + u2 = -1

The u term is -3u.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3u + 2.25 + u2 = -1 + 2.25

Reorder the terms:
2.25 + -3u + u2 = -1 + 2.25

Combine like terms: -1 + 2.25 = 1.25
2.25 + -3u + u2 = 1.25

Factor a perfect square on the left side:
(u + -1.5)(u + -1.5) = 1.25

Calculate the square root of the right side: 1.118033989

Break this problem into two subproblems by setting 
(u + -1.5) equal to 1.118033989 and -1.118033989.

Subproblem 1
u + -1.5 = 1.118033989

Simplifying
u + -1.5 = 1.118033989

Reorder the terms:
-1.5 + u = 1.118033989

Solving
-1.5 + u = 1.118033989

Solving for variable 'u'.

Move all terms containing u to the left, all other terms to the right.

Add '1.5' to each side of the equation.
-1.5 + 1.5 + u = 1.118033989 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + u = 1.118033989 + 1.5
u = 1.118033989 + 1.5

Combine like terms: 1.118033989 + 1.5 = 2.618033989
u = 2.618033989

Simplifying
u = 2.618033989

Subproblem 2
u + -1.5 = -1.118033989

Simplifying
u + -1.5 = -1.118033989

Reorder the terms:
-1.5 + u = -1.118033989

Solving
-1.5 + u = -1.118033989

Solving for variable 'u'.

Move all terms containing u to the left, all other terms to the right.

Add '1.5' to each side of the equation.
-1.5 + 1.5 + u = -1.118033989 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + u = -1.118033989 + 1.5
u = -1.118033989 + 1.5

Combine like terms: -1.118033989 + 1.5 = 0.381966011
u = 0.381966011

Simplifying
u = 0.381966011

Solution
The solution to the problem is based on the solutions
from the subproblems.
u = {2.618033989, 0.381966011}