Consider the boundary-value problem $ y''- 2y' + 2y = 0 $, $ y(a) = c $, $ y(b) = d $.
(a) If this problem has a unique solution, how are $ a $ and $ b $ related?
(b) If this problem has no solution, how are $ a $, $ b $, $ c $, and $ d $ related?
(c) If this problem has infinitely many solutions, how are $ a $, $ b $, $ c $, and $ d $ related?