Consider the one-dimensional heat equation:
∂u/∂t = α(∂²u/∂x²)
a. Determine the Green's function for this equation in infinite space.
b. Solve this equation using the Green's function for infinite space and the concept of superposition, subject to the following boundary and initial conditions:
u(0,t) = 0 and u(L,t) = 0
u(x,0) = f(x)
c. Is it possible to determine the time for which this semi-infinite medium solution fails to represent for a given rod length L?