The homework question I have is"For the second, fourth, sixth, and seventh levels of the three-dimensional cubical box, find the energies in terms of the quantity E0 π2ℏ2/(2mL2), where m is the particle mass and L is the box's sidelength."However, I'm not confused on how to solve it. The question I have is this - in this situation, how would I determine what the nx, ny, and nz would be for each new energy level? I know you can use a table, but I'm not going to have that in a test situation. How do I determine that the 6th energy level should be (3^2 +2^2 +1^2)?