AP EAMCET Engineering 17 Sep 2020 Shift 2 Paper

General solution of differential equation is,

Here solution is of form;
y=A‌sin(x+C3)+Bex
[∵C1+C2=A,C4ec=B]
So, there are 3 -arbitrary constants, A1C3 and B
Now, order of differential equation = number of arbitrary constants in general solution.
So, order of differential equation is 3.