Exponential graphs of the form f(x) = a^x have a similar shape graph to the graphs of their gradient functions. When original and gradient function graphs are identical, a = e.
log a (n) = x is equivalent toa^x =n.
log a (x) + log a (y) = log a (x y).
log a (x) - log a (y) = log a (x/y).
log a (x^k) = k log a (x).
log a (1/x) = - log a (x)
log a (a) = 1.
log a (1) = 0.
The graph of y = ln x is a reflection of the graph y = e^x in the line y = x.