Linear differential equations of second order- Linear independence of solutions . Solution by transformation of the equations by changing the dependent and independent variable. Factorization of operators. Method of variation of parameters, Method of undetermined coefficients.
Links:
[1] https://maths.iisuniv.ac.in/courses/subjects/differential-equations-2
[2] https://maths.iisuniv.ac.in/academic-year/2015-2016