Answer
(a) Please see below.
(b) $$f(x)=x, \qquad g(x)=\begin{cases}x & x\neq 1 \\2 & x=1 \end{cases}$$
Work Step by Step
(a) This means that the values of the two functions at every point of the domain are the same except at one point; that is, there exists only one point in the domain such that the values of the two functions differ from each other.
(b) Consider the following functions:$$f(x)=x, \qquad g(x)=\begin{cases}x & x\neq 1 \\2 & x=1 \end{cases}.$$It is clear that the two functions $f(x)$ and $g(x)$ have the same values at every point except $x=1$, where $f(1)=1 \neq 2 = g(1)$.