81k^2-1=0

Solution for 81k^2-1=0 equation:

Simplifying
81k2 + -1 = 0

Reorder the terms:
-1 + 81k2 = 0

Solving
-1 + 81k2 = 0

Solving for variable 'k'.

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

Add '1' to each side of the equation.
-1 + 1 + 81k2 = 0 + 1

Combine like terms: -1 + 1 = 0
0 + 81k2 = 0 + 1
81k2 = 0 + 1

Combine like terms: 0 + 1 = 1
81k2 = 1

Divide each side by '81'.
k2 = 0.01234567901

Simplifying
k2 = 0.01234567901

Take the square root of each side:
k = {-0.111111111, 0.111111111}