Question

I'm totally confused about this PDE problem.

Answer 1

Here's the example it's based on.

Answer 2

the function is of only one variable so it is solved like ODE

Answer 3

what function?

Answer 4

u(x)

Answer 5

but not sure it's sinh and cosh instead of sin and cos

Answer 6

I posted an example and an exercise. I'm confused about both of them. Are talking about u(x) in the example? If so, I do not understand what ODE method they actually used to solve it.

Answer 7

\[D u''- r u=0\]


\[u''=(r/D) u\]

\[\lambda^2=r/D\]

\[u= C e^{\sqrt{r/D}t}+C_2 e^{-\sqrt{r/D}t} \]

Answer 8

What method is that?

Answer 9

just solving 2nd order linear oridnary equation