




e^{x} is defined on [, +]
e^{0} = 1
e^{1} = e = 2.71828...
The inverse function to e^{x} is called ln x.
ln(e^{x}) = e^{lnx} = x
ln(x) is defined on ]0, +] and its graph is obtained by reflecting the graph y = e^{x} with respect to the line y = x.
ln(1) = 0
ln(e) = 1