A rod of length `L` and cross-section area `A` lies along the x-axis between `x=0` and `x=L`. The material obeys Ohm's law and its resistivity varies along the rod according to `rho(x) = rho_0 epsilon^(-x//L)`. The end of the rod `x=0` is at a potential `V_0` and it is zero at `x=L`.
(a) Find the total resistance of the rod and the current in the wire.
(b) Find the electric potential in the rod as a function of `x`.

Explanation

To solve the problem step by step, we will break it down into parts (a) and (b) as given in the question.

### Part (a): Finding the Total Resistance of the Rod and the Current in the Wire

1. **Understanding the Resistance of a Differential Element**:
The resistivity of the rod varies with position \( x \) according to the formula:
\[
\rho(x) = \rho_0 e^{-x/L}
...