8x^4+x^2-8=0

Solution for 8x^4+x^2-8=0 equation:

Simplifying
8x4 + x2 + -8 = 0

Reorder the terms:
-8 + x2 + 8x4 = 0

Solving
-8 + x2 + 8x4 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
8 the coefficient of the squared term: 

Divide each side by '8'.
-1 + 0.125x2 + x4 = 0

Move the constant term to the right:

Add '1' to each side of the equation.
-1 + 0.125x2 + 1 + x4 = 0 + 1

Reorder the terms:
-1 + 1 + 0.125x2 + x4 = 0 + 1

Combine like terms: -1 + 1 = 0
0 + 0.125x2 + x4 = 0 + 1
0.125x2 + x4 = 0 + 1

Combine like terms: 0 + 1 = 1
0.125x2 + x4 = 1

The x term is x2.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
0.125x2 + 0.25 + x4 = 1 + 0.25

Reorder the terms:
0.25 + 0.125x2 + x4 = 1 + 0.25

Combine like terms: 1 + 0.25 = 1.25
0.25 + 0.125x2 + x4 = 1.25

Factor a perfect square on the left side:
(x2 + 0.5)(x2 + 0.5) = 1.25

Calculate the square root of the right side: 1.118033989

Break this problem into two subproblems by setting 
(x2 + 0.5) equal to 1.118033989 and -1.118033989.

Subproblem 1
x2 + 0.5 = 1.118033989

Simplifying
x2 + 0.5 = 1.118033989

Reorder the terms:
0.5 + x2 = 1.118033989

Solving
0.5 + x2 = 1.118033989

Solving for variable 'x'.

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

Add '-0.5' to each side of the equation.
0.5 + -0.5 + x2 = 1.118033989 + -0.5

Combine like terms: 0.5 + -0.5 = 0.0
0.0 + x2 = 1.118033989 + -0.5
x2 = 1.118033989 + -0.5

Combine like terms: 1.118033989 + -0.5 = 0.618033989
x2 = 0.618033989

Simplifying
x2 = 0.618033989

Take the square root of each side:
x = {-0.786151378, 0.786151378}

Subproblem 2
x2 + 0.5 = -1.118033989

Simplifying
x2 + 0.5 = -1.118033989

Reorder the terms:
0.5 + x2 = -1.118033989

Solving
0.5 + x2 = -1.118033989

Solving for variable 'x'.

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

Add '-0.5' to each side of the equation.
0.5 + -0.5 + x2 = -1.118033989 + -0.5

Combine like terms: 0.5 + -0.5 = 0.0
0.0 + x2 = -1.118033989 + -0.5
x2 = -1.118033989 + -0.5

Combine like terms: -1.118033989 + -0.5 = -1.618033989
x2 = -1.618033989

Simplifying
x2 = -1.618033989

Reorder the terms:
1.618033989 + x2 = -1.618033989 + 1.618033989

Combine like terms: -1.618033989 + 1.618033989 = 0.000000000
1.618033989 + x2 = 0.000000000

The solution to this equation could not be determined.This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.