Unlike equations of the first-order and first-degree linear (ODE)’s that are second and higher order, and have variable coefficients, are often difficult to solve. Fortunately, there are equations of special types that are easier to handle. Some of these were treated in the preceding chapter. Different from special types, but somewhat in the same vein, are equations that represent ‘Special Situations’. With such situations in place, satisfactory solution is often possible. For instance, a given differential equation may be integrable. Similarly, equations that have both the independent as well as the dependent variables missing in any explicit form: And those that explicitly contain only the independent variable, or only the dependent variable, are easily handled.