We explore 3 different explanations why the solution is of the form (A + Bx) e^{lambda x}, for a 2nd order linear homogeneous differential equation whose auxiliary equation has repeated root lambda.
00:00 Intro
00:38 Background: Distinct roots case
06:59 Explanation 1: Reduction of order derivation
10:36 Explanation 2: Variation of parameters
15:39 Explanation 3: Taking limits