Final answer:
The student needs to apply a method from a previous problem to find a particular solution to a nonhomogeneous second-order linear equation, using a complementary function that has been provided.
Step-by-step explanation:
The student's question involves finding a particular solution to a nonhomogeneous second-order linear equation given a complementary function yn. The method referred to in Problem 57 is likely a systematic approach to solving such equations, possibly involving the use of an ansatz, or a guessed form of the solution, which would then be adjusted to satisfy the given equation.
In general, when solving for a particular solution, one might consider several different approaches such as undetermined coefficients or variation of parameters, depending on the form of the nonhomogeneous term. While the exact method of Problem 57 is not provided, the task is to apply that method to find a particular solution that works in conjunction with the complementary function to satisfy the overall equation. This process typically involves substituting the postulated particular solution into the differential equation and solving for any unknown constants to meet the conditions of the problem.