In: Physics
t2 (d2r/dt2) - 9t (dr/dt) + 16r = 4 is an example of a "Cauchy-Euler equation." Such equations appear in a number of physics and engineering applications.
a) Write the complementary homogeneous equation.
b) Plug r = ekt into the equation you wrote in part a. Show that this solution will not work for any constant k: this equation has no exponential solution.
c) Plug the guess r = tn (where n is a constant) into the equation you wrote for part a. Solve the resulting algebraic equation for n; you should find 2 solutions.
d) Write the general solution to the equation you wrote in Part a.
e) Find a specific solution to the origianl (inhomogeneous) equation.
f) Write the general solution to the inhomogeneous equation.
g) What is it about this particular equation that made r = tn work?