Solve the differential equation (D4 + 16D2)y = x2 + 5
Given (D4 + 16D2)y = x2 + 5. …(1)
A.E., D4 + 16D2 = 0
i.e. D2(D2 + 16) = 0 or D = 0, 0, ±4i … (2)
Thus, the complementary function,
C.F. = (c1 + c2x) + (c3cos4x + c4sin4x) … (3)
For particular integral,