Let Ω be a cone in Rn with n≥2. For every fixed
α∈R we find the best constant in the Rellich inequality
∫Ω∣x∣α∣Δu∣2dx≥C∫Ω∣x∣α−4∣u∣2dx for u∈Cc2(Ωˉ∖{0}). We also estimate the best constant for
the same inequality on Cc2(Ω). Moreover we show improved Rellich
inequalities with remainder terms involving logarithmic weights on cone-like
domains