y^4-1=0

Solution for y^4-1=0 equation:

Simplifying
y4 + -1 = 0

Reorder the terms:
-1 + y4 = 0

Solving
-1 + y4 = 0

Solving for variable 'y'.

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

Add '1' to each side of the equation.
-1 + 1 + y4 = 0 + 1

Combine like terms: -1 + 1 = 0
0 + y4 = 0 + 1
y4 = 0 + 1

Combine like terms: 0 + 1 = 1
y4 = 1

Simplifying
y4 = 1

Reorder the terms:
-1 + y4 = 1 + -1

Combine like terms: 1 + -1 = 0
-1 + y4 = 0

Factor a difference between two squares.
(1 + y2)(-1 + y2) = 0

Factor a difference between two squares.
(1 + y2)((1 + y)(-1 + y)) = 0

Subproblem 1
Set the factor '(1 + y2)' equal to zero and attempt to solve:

Simplifying
1 + y2 = 0

Solving
1 + y2 = 0

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

Add '-1' to each side of the equation.
1 + -1 + y2 = 0 + -1

Combine like terms: 1 + -1 = 0
0 + y2 = 0 + -1
y2 = 0 + -1

Combine like terms: 0 + -1 = -1
y2 = -1

Simplifying
y2 = -1

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 '(1 + y)' equal to zero and attempt to solve:

Simplifying
1 + y = 0

Solving
1 + y = 0

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

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

Combine like terms: 1 + -1 = 0
0 + y = 0 + -1
y = 0 + -1

Combine like terms: 0 + -1 = -1
y = -1

Simplifying
y = -1
Subproblem 3
Set the factor '(-1 + y)' equal to zero and attempt to solve:

Simplifying
-1 + y = 0

Solving
-1 + y = 0

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

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

Combine like terms: -1 + 1 = 0
0 + y = 0 + 1
y = 0 + 1

Combine like terms: 0 + 1 = 1
y = 1

Simplifying
y = 1
Solution
y = {-1, 1}