NCERT Example 19 - Differential Equations
Question: Verify that y = c1 e^{ax} cos bx + c2 e^{ax} sin bx is a solution of y'' - 2a y' + (a^2+b^2)y = 0.
Answer: Verified / is a solution.
Full step-by-step NCERT solution with diagrams on Something by Zero.