sub, systems of DE

Homogeneous in degree type - f(linear) type - systems of DE - intro to the 2nd-order ODE

linear operator, uniqueness Theorem

Linear operator - Uniqueness Theorem for 2nd order IVP

Wronskian

Def. of Wronskian, a fundamental set of solutions - Thm about Wronskian that it is constantly zero or never zero

2nd order homogeneous DE with constant coefficients

Theorem on LI/LD and Wronskian of the solutions - 2nd order linear homogeneous DE with constant coefficients: characteristic equation, distinct roots and complex roots cases

Reduction of order, Variation of Parameters

how to find y2 given y1 in the 2nd order homogeneous DE (Reduction of order) - how to determine a particular solution of a nonhomogenous DE (Variation of parameters)