11.
The respective expressions for complimentary function and particular integral part of the solution of the differential equation $$\frac{{{{\text{d}}^4}{\text{y}}}}{{{\text{d}}{{\text{x}}^4}}} + 3\frac{{{{\text{d}}^2}{\text{y}}}}{{{\text{d}}{{\text{x}}^2}}} = 108{{\text{x}}^2}$$    are

12.
The solution of the differential equation $$\frac{{{{\text{d}}^2}{\text{y}}}}{{{\text{d}}{{\text{t}}^2}}} + 2\frac{{{\text{dy}}}}{{{\text{dt}}}} + {\text{y}} = 0$$     with y(0) = y'(0) = 1 is

13.
Consider the differential equation $$\left( {{{\text{t}}^2} - 81} \right)\frac{{{\text{dy}}}}{{{\text{dt}}}} + 5{\text{ty}} = \sin \left( {\text{t}} \right)$$      with y(1) = 2π. There exists a unique solution for this differential equation when t belongs to the interval

15.
Which one of the following is the general solution of the first order differential equation $$\frac{{{\text{dy}}}}{{{\text{dx}}}} = {\left( {{\text{x}} + {\text{y}} - 1} \right)^2},$$    where x, y are real?

16.
If roots of the auxiliary equation of $$\frac{{{{\text{d}}^2}{\text{y}}}}{{{\text{d}}{{\text{x}}^2}}} + {\text{a}}\frac{{{\text{dy}}}}{{{\text{dx}}}} + {\text{by}} = 0$$     are real and equal, the general solution of the differential equation is

17.
The solution of the ordinary differential equation $$\frac{{{\text{dy}}}}{{{\text{dx}}}} + {\text{2y}} = 0$$   for the boundary condition, y = 5 at x = 1 is

18.
If y is the solution of the differential equation
$$\eqalign{ & {{\text{y}}^3}\frac{{{\text{dy}}}}{{{\text{dx}}}} + {{\text{x}}^3} = 0, \cr & {\text{y}}\left( 0 \right) = 1 \cr} $$
the value of y(-1) is

19.
The general solution of the differential equation $$\frac{{{\text{dy}}}}{{{\text{dx}}}} = \cos \left( {{\text{x}} + {\text{y}}} \right),$$    with c as a constant, is

20.
The solution of the differential equation, $$\frac{{{{\text{d}}^2}{\text{y}}}}{{{\text{d}}{{\text{x}}^2}}} - \frac{{{\text{dy}}}}{{{\text{dx}}}} - 2{\text{y}} = 3{{\text{e}}^{2{\text{x}}}},$$     where, y(0) = 0 and y'(0) = -2 is