1. The problem statement, all variables and given/known data A Spherical potential which is 0 for 0<r<a Vo for r>a Find the condition for bound states, for the radial function with l=0 Plot the result. 3. The attempt at a solution I have gotten the equation - tan(ka)=k/lambda where k is the wavenumber for the wave inside the well and lambda is the wavenumber for the wave outside the wave. I know these kind of equation have to be solved graphically or numerically. I have a similiar equation solved graphically in my textbook but I dont understand it. Can anyone please help me and give me a hint to how to solve this transcendental equation?