# Example of a function in Sobolev-Slobodeskji space

How do i show that $u(r,\theta) = r^\lambda sin(\lambda \theta)$ belongs to $H^{1+\lambda}(\Omega),$ with $\lambda \in (0,1)$ for $\Omega \subset \mathbb{R}^2$?

• $\Omega$ is probably an open set containing the origin. – Giuseppe Negro Apr 27 '17 at 21:16
• @GiuseppeNegro yes. – uli.xu Apr 27 '17 at 22:04