Problem about Leonard-Jones interaction (Energy)

A commonly used potential energy function to describe the interaction between two atoms is the

LENNARD-JONES 6,12 potential

U = e{ (Ro/R)^12 - 2(Ro/R)^6 }

the problem is accompanied with a graph representing U in function of R, the curve begines at a certain point above the R axis , then decreases continuously, crosses the R axis and has a minimum at the coordinate (Ro,e), then decrease anew but stays below the R axis which becomes an horizontal asymptot for the curve .

Show that the radius at the potential minimum is Ro, and that the depth of the potential well is e.

then, find the frequency of small oscillations about equilibium for 2 identical atoms of mnass m bound to each other by the Leonard-Jones interaction.