Logarithmic Functions Examples

Let f(z) = ln z. Find f ' (z).

Let f(x) = ln 4. Find f ' (x).

This is a trick question. Since ln 4 is a number, this is a constant function. Its derivative is 0, therefore

f ' (x) = 0.

There are only so many questions we can ask right now. We'll find derivatives of logarithmic functions with different bases after we introduce another rule . For now, we'll get used to the notation.