Math 322 Exam 2 Preparation
  1. Series Solutions to differential equations.

    1. Determine whether a point is an ordinary point or a singular point for an ODE. If it is a singular point, determine whether it is regular.

    2. Determine the radius of convergence of a power series solution about an ordinary point. Determine the interval of convergence.

    3. Find a power series about an ordinary point. Note: This involves guessing a normal power series as a solution, and is not the method of Frobenius.
      • Change indices of summation as needed to combine sums.
      • Obtain a recurrence relation to find subsequent coefficients.
      • Find enough coefficients to identify any obvious patterns.
      • Give the final solution or solutions.

    4. Apply the method of Frobenius to find a series solution about a regular singular point.
      • Change indices of summation as needed to combine sums.
      • Obtain a recurrence relation to find subsequent coefficients.
      • Find and solve the indicial equation.
      • Determine whether any coefficients must be zero.
      • Find enough coefficients to identify any obvious patterns.
      • Give the final solution or solutions.

  2. Systems of Differential Equations

    1. Find the homogeneous solution to a system of differential equations. This was tested on Exam 1, but is needed again here.

    2. Sketch the phase portrait for a homogeneous system of two first order ODEs.

    3. Determine whether the origin is a nodal sink, nodal source, spiral sink, spiral source, saddle point or center for a system of two first order ODEs. (You do not have to classify the type of node if the origin is a node.) Determine whether a system is unstable, neutrally stable or asymptotically stable.

    4. Find a particular solution to a system of ODEs using
      • the method of undetermined coefficients, with the guess for the particular solution given
      • the method of variation of parameters

    5. Solve a non-homogeneous system or an IVP for a non-homogeneous system.
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