## Log Book

A logbook is a chronological record of events or activities, often used in various fields such as aviation, maritime, scientific research, and more. It serves as a detailed record of important information, observations, or transactions.

The first two digits of these 4 digits give the row number, the 3^{rd} digit is the column number, and the 4^{th} digit is the mean difference. Just find the number in the log table that is in the intersection point of the row and column and add the mean difference of the 4^{th} digit of the same row to that number.

### Logarithmic Table

### Logarithmic Function Definition

The logarithmic function is defined as an inverse function to exponentiation. The logarithmic function is stated as follows

For x, a > 0, and a≠1,

**y= log _{a }x, if x = a^{y}**

Then the logarithmic function is written as:

**f(x) = log _{a }x**

The most common bases used in logarithmic functions are base e and base 10. The log function with base 10 is called the common logarithmic function and it is denoted by log_{10} or simply log.

**f(x) = log _{10}**

The log function to the base e is called the natural logarithmic function and it is denoted by log_{e}^{.}

**f(x) = log _{e} x**