4-81u^2=

Solution for 4-81u^2= equation:

Simplifying
4 + -81u2 = 0

Solving
4 + -81u2 = 0

Solving for variable 'u'.

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

Add '-4' to each side of the equation.
4 + -4 + -81u2 = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -81u2 = 0 + -4
-81u2 = 0 + -4

Combine like terms: 0 + -4 = -4
-81u2 = -4

Divide each side by '-81'.
u2 = 0.04938271605

Simplifying
u2 = 0.04938271605

Take the square root of each side:
u = {-0.222222222, 0.222222222}