This means that you write u ( r , θ ) = R ( r ) Θ ( θ ) {\displaystyle u(r,\theta )=R(r)\Theta (\theta )} .
Det innebär att man skriver u ( r , θ ) = R ( r ) Θ ( θ ) {\displaystyle u(r,\theta )=R(r)\Theta (\theta )} .