# condition number

Well, the site you link to gives the "relative condition number" as $\frac{||J||||x||}{||f(x)||}$ and further notes that if f is a real valued function of a single real variable, that reduces to $\frac{|f'(x)||x|}{|f(x)|}$. In your example, f(x)= exp(x), f'(x) is also exp(x) so they cancel and your are almost correct- the relative condition number is |x|.