find the green function for the differential operator L $=($d$/$dr$)($r$^2)($d$/$dr$)$ on the interval a $<=$ r $<$ inf with homogeneous Dirichlet boundary conditions; i$.$e$.,$ solve for G$($r$,$ r$\text{'})$ where $($d$/$dr$)($r$^2)($dG$($r$,$r$\text{'})/$dr$)=-$ delta$($r$-$r$\text{'})$ on $[$a$,$ inf$)$ where G$($a$,$r$\text{'})=$ G$($inf$,$ r$\text{'})=0.$ One method of solution involves indefinite integrals, Note that $\{$f$($x$)-$f$($x$\text{'})\}$ delta$($x$-$x$\text{'})=0$ so that $($d$/$dx$)(\{$f$($x$)-$f$($x$\text{'})\}$ theta$($x$-$x$\text{'}))=($df$($x$)/$dx$)($theta$)($x$-$x$\text{'}).$