In mathematics, the Ince equation, named for Edward Lindsay Ince, is the differential equation
w\prime\prime+\xi\sin(2z)w\prime+(η-p\xi\cos(2z))w=0.
When p is a non-negative integer, it has polynomial solutions called Ince polynomials. In particular, when
p=1,η\pm\xi=1
w(z)=Ce-iz(e2iz\mp1)
where
C