# How do a find the answer for the log of something that isnt base 10?

• February 3rd 2010, 02:16 AM
appleseed
How do a find the answer for the log of something that isnt base 10?
This is the question:
Im just curious as to whether its even possible to solve this, because they want me to find the derivative, and the inverse of it (Thinking)
Thankyou!
http://img148.imageshack.us/img148/1610/79729214.png
• February 3rd 2010, 02:21 AM
mr fantastic
Quote:

Originally Posted by appleseed
This is the question:
Im just curious as to whether its even possible to solve this, because they want me to find the derivative, and the inverse of it (Thinking)
Thankyou!

Note that $2^x = e^{ln 2^x} = e^{(ln 2) x}$.

To get the inverse, the usual approach is to swap around y and x and then make y the subject.