Form the differential equation by eliminating the arbitrary constant from the equation `y = a cos (2x + b)`

Form the differential equation by eliminating the arbitrary constant from the equation y = a cos x + b sin x + x sin x

Form the differential equation by eliminating the arbitrary constant from the equation y = ax^(3) + bx^(2)

Form the differential equation by eliminating the arbitrary constant from the equation xy = ae^(x) + be^(-x) + x^(2)