Skill List for Exam III

Please plan to attend the review session. More complete information will be given there.

Exam III covers sections 5.4 - 5.7 on series solutions at regular singular points, and Chapter 6 on Laplace transform methods.
Important skills include the following.
  • For 2nd order linear homogeneous equations Py'' + Qy' + Ry = 0, where P(0) = 0, so 0 is a singular point, classify 0 as regular or not
  • Solve equations and IVPs of Euler type
  • For more general equations where 0 is a regular singular point, find the indicial equation
  • If r1 >= r2 are real roots of the indicial equation, there is always a solution of the form x^r1 times a power series. Find it.
  • Identify piecewise continuous functions
  • Use the (supplied) table of Laplace transforms to pass back and forth between f(t) and F(s)
  • Use the theorems on transforms of f " and f ' to find their transforms in terms of the transform of f.
  • Solve IVP's where the transform F(s) is actually in the table.
  • Be acquainted with unit step function u-sub-c(t) and the translation of a function f(t) to c.
  • Use the inverse transforms of (e^-cs)F(s) and F(s - c) to solve IVPs
  • Use the above to solve IVPs Ly = g(t) where g(t) involves step functions.
  • Understand modeling using the Dirac delta "function", delta(t - a) = unit impulse instantaneous force at t = a
  • Know transform of delta
  • Solve undamped IVPs of form Ly = g(t), where g(t) involves delta.
  • Same for damped IVPs
  • Compute convolution f*g of f(t) and g(t)
  • Know properties of transforms and inverse transforms in connection with *
  • Express solution of Ly = g(t), y(0)=., y'(0) = . in terms of the convolution of g(t) with some other function.