List of top Mathematics Questions on Partial Differential Equations asked in AP ECET Metallurgical Eng, AP ECET ECE

If $(x/a)^n + (y/b)^n = 2$, then $dy/dx$ at $(a,b)$ is
Particular integral of $f(D)y = \cos ax$ is
Complementary function of the differential equation $(D^3 - 8)y = x$ is