Editing Exponential growth (section)

==Reformulation as log-linear growth==
If a variable {{mvar|x}} exhibits exponential growth according to <math>x(t) = x_0 (1+r)^t</math>, then the log (to any base) of {{mvar|x}} [[linear function|grows linearly]] over time, as can be seen by taking [[logarithm]]s of both sides of the exponential growth equation:
<math display="block">\log x(t) = \log x_0 + t \cdot \log (1+r).</math>

This allows an exponentially growing variable to be modeled with a [[Nonlinear regression#Linearization|log-linear model]]. For example, if one wishes to empirically estimate the growth rate from intertemporal data on {{mvar|x}}, one can [[linear regression|linearly regress]] {{math|log ''x''}} on {{mvar|t}}.