Logarithms

The RPD-95 can perform calculations involving common and natural logarithms and their inverses (antilogarithms).

Logarithms

The [ LN ] key calculates the natural (base e) logarithm of a number in the display. The [ LOG ] key calculates the common (base 10) logarithm of a number in the display. These functions require a positive input value.

Antilogarithms

The key sequence [ INV ][ LN ] calculates the natural antilogarithm of a number in the display. The natural antilogarithm function can be thought of as e^x.

The key sequence [ INV ][ LOG ] calculates the common antilogarithm of a number in the display. The common antilogarithm function can be thought of as 10^x.

Example

The following example illustrates the operation of the logarithm and antilogarithm functions.

Procedure	Press	Display
Clear display	[ CLEAR ]
Enter a number	83
Calculate the common logarithm	[ LOG ]
Calculate the common antilogarithm	[ INV ] [ LOG ]
Calculate the natural log	[ LN ]
Calculate the natural antilogarithm	[ INV ] [ LN ]