2x^4-21x^2-11=

Solution for 2x^4-21x^2-11= equation:

Simplifying
2x4 + -21x2 + -11 = 0

Reorder the terms:
-11 + -21x2 + 2x4 = 0

Solving
-11 + -21x2 + 2x4 = 0

Solving for variable 'x'.

Factor a trinomial.
(-1 + -2x2)(11 + -1x2) = 0

Subproblem 1
Set the factor '(-1 + -2x2)' equal to zero and attempt to solve:

Simplifying
-1 + -2x2 = 0

Solving
-1 + -2x2 = 0

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

Add '1' to each side of the equation.
-1 + 1 + -2x2 = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -2x2 = 0 + 1
-2x2 = 0 + 1

Combine like terms: 0 + 1 = 1
-2x2 = 1

Divide each side by '-2'.
x2 = -0.5

Simplifying
x2 = -0.5

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.
Subproblem 2
Set the factor '(11 + -1x2)' equal to zero and attempt to solve:

Simplifying
11 + -1x2 = 0

Solving
11 + -1x2 = 0

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

Add '-11' to each side of the equation.
11 + -11 + -1x2 = 0 + -11

Combine like terms: 11 + -11 = 0
0 + -1x2 = 0 + -11
-1x2 = 0 + -11

Combine like terms: 0 + -11 = -11
-1x2 = -11

Divide each side by '-1'.
x2 = 11

Simplifying
x2 = 11

Take the square root of each side:
x = {-3.31662479, 3.31662479}
Solution
x = {-3.31662479, 3.31662479}