For \(a\in (0,1)\) , let \(\mathcal {H}_0(a)\) denote the class of analytic functions f in the unit disk \(\mathbb {D}=\{z\in \mathbb {C}: |z|<1\}\) satisfying \(f(0) =0\) and \(f'(0)=a\) , and let \(\mathcal {B}_0(a)\) be the subclass of \(\mathcal {H}_0(a)\) consisting of functions bounded in modulus by 1. Let \(\mathcal {B}_0(a,1)\) be the subclass of \(\mathcal {B}_0(a)\) of functions having no nonzero zeros. We determine several starlikeness radii for \(\mathcal {B}_0(a,1)\) . Furthermore, we introduce the class \(\Omega ^a:=\{ f\in \mathcal {H}_0(a): |zf'(z)-f(z)|<1/2\}\) and compute various sharp radii of reciprocal starlikeness for functions in the class \(\Omega ^a\) .