The order of differential equation of family of curves given by y=a1(a2+a3)⋅cos(x+a4)−a5ex+a6, is
Substitute λ1=a1(a2+a3)
λ2=−a5⋅ea6
y=λ1cos(x+a4)−a5⋅ex⋅ea6=λ1cos(x+a4)−λ2ex
we made it to least number of arbitrary constants.
So the order is the total number of arbitrary constants
Therefore order is 3