d^2-2d-2=0

Solution for d^2-2d-2=0 equation:

Simplifying
d2 + -2d + -2 = 0

Reorder the terms:
-2 + -2d + d2 = 0

Solving
-2 + -2d + d2 = 0

Solving for variable 'd'.

Begin completing the square.

Move the constant term to the right:

Add '2' to each side of the equation.
-2 + -2d + 2 + d2 = 0 + 2

Reorder the terms:
-2 + 2 + -2d + d2 = 0 + 2

Combine like terms: -2 + 2 = 0
0 + -2d + d2 = 0 + 2
-2d + d2 = 0 + 2

Combine like terms: 0 + 2 = 2
-2d + d2 = 2

The d term is -2d.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2d + 1 + d2 = 2 + 1

Reorder the terms:
1 + -2d + d2 = 2 + 1

Combine like terms: 2 + 1 = 3
1 + -2d + d2 = 3

Factor a perfect square on the left side:
(d + -1)(d + -1) = 3

Calculate the square root of the right side: 1.732050808

Break this problem into two subproblems by setting 
(d + -1) equal to 1.732050808 and -1.732050808.

Subproblem 1
d + -1 = 1.732050808

Simplifying
d + -1 = 1.732050808

Reorder the terms:
-1 + d = 1.732050808

Solving
-1 + d = 1.732050808

Solving for variable 'd'.

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

Add '1' to each side of the equation.
-1 + 1 + d = 1.732050808 + 1

Combine like terms: -1 + 1 = 0
0 + d = 1.732050808 + 1
d = 1.732050808 + 1

Combine like terms: 1.732050808 + 1 = 2.732050808
d = 2.732050808

Simplifying
d = 2.732050808

Subproblem 2
d + -1 = -1.732050808

Simplifying
d + -1 = -1.732050808

Reorder the terms:
-1 + d = -1.732050808

Solving
-1 + d = -1.732050808

Solving for variable 'd'.

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

Add '1' to each side of the equation.
-1 + 1 + d = -1.732050808 + 1

Combine like terms: -1 + 1 = 0
0 + d = -1.732050808 + 1
d = -1.732050808 + 1

Combine like terms: -1.732050808 + 1 = -0.732050808
d = -0.732050808

Simplifying
d = -0.732050808

Solution
The solution to the problem is based on the solutions
from the subproblems.
d = {2.732050808, -0.732050808}