Let \[ f=x_+^\lambda = \begin {cases} 0, & x\le 0,\\ x^\lambda , & x>0, \end {cases} \] where \(-1<\lambda <0\). Then \(f\in L^1_{\operatorname {loc}}(\mathbb {R})\), hence \(f\) may be thought of as a distribution.
Compute \(\partial f\). Note that \(\partial f/\partial x\notin L^1_{\operatorname {loc}}(\mathbb {R})\).