| m | d²x | + αx = − He | dy | ; |
| dt² | dt |
| m | d²y | + αy = He | dx | ; |
| dt² | dt |
| m | d²z | + ax = 0. |
| dt² |
The solution of these equations is
| x = A cos (p1t + β) + B cos (p2t + β1) |
| y = A sin (p1t + β) − B sin (p2t + β1) |
| z = C cos (pt + γ) |
where
| α − mp1² = − Hep1 |
| α − mp2² = Hep2 |
p² = α / m,
or approximately
| p1 = p + ½ | He | , p2 = p − ½ | He | . |
| m | m |