b^4+2b^2-15=0

Solution for b^4+2b^2-15=0 equation:

Simplifying
b4 + 2b2 + -15 = 0

Reorder the terms:
-15 + 2b2 + b4 = 0

Solving
-15 + 2b2 + b4 = 0

Solving for variable 'b'.

Factor a trinomial.
(-5 + -1b2)(3 + -1b2) = 0

Subproblem 1
Set the factor '(-5 + -1b2)' equal to zero and attempt to solve:

Simplifying
-5 + -1b2 = 0

Solving
-5 + -1b2 = 0

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

Add '5' to each side of the equation.
-5 + 5 + -1b2 = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -1b2 = 0 + 5
-1b2 = 0 + 5

Combine like terms: 0 + 5 = 5
-1b2 = 5

Divide each side by '-1'.
b2 = -5

Simplifying
b2 = -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 '(3 + -1b2)' equal to zero and attempt to solve:

Simplifying
3 + -1b2 = 0

Solving
3 + -1b2 = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1b2 = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1b2 = 0 + -3
-1b2 = 0 + -3

Combine like terms: 0 + -3 = -3
-1b2 = -3

Divide each side by '-1'.
b2 = 3

Simplifying
b2 = 3

Take the square root of each side:
b = {-1.732050808, 1.732050808}
Solution
b = {-1.732050808, 1.732050808}