How to Solve Derivatives with Logarithmic Functions
Description
This video covers the basic exponential and logarithmic functions, and then shows several sample problems. Many example problems of solving for natural logs are provided in the video. This video also shows the relationship between exponents and natural logs.
Overview
Derivatives with logarithms are rather easy to solve. The first of these is the regular exponent. The exponent is an exponential function, not a logarithmic function, but the two are related. The solution for an exponent, e^x, is:
d/dx (e^x) = e^x
Remember that the exponential solution only works when the variable x is the exponent, and to not use this when you should be using the power rule. The two look very similar and it is easy to mix them up. A problem using the power rule looks like x^2. A problem using the exponential rule looks like 2^x.
The next of these is a natural log. A natural log is a logarithm in its natural form. It is not necessary to understand natural logs to solve a derivative problem with natural logs. This should be a derivative that you have memorized. The natural log is solved like this:
d/dx [ln(x)] = 1 / x
In other words, to solve a natural log simply put one over whatever is inside the parenthesis. Remember that it may be necessary to use other rules with this rule.




