LN

Member Of Menu: 
Logs
Argument Types: 
Real
Complex
Symbol
Expression
Result Type(s): 
Real
Complex
Expression
Invertible: 
Yes
Valid In Expression: 
Yes
Stack Diagram: 
Real1 → Real2
Real1 → Complex2
Complex1 → Complex2
Symbol1 → Expression2
Expression1 → Expression2

This operation calculates the natural logarithm (base e) of its input argument. If the argument is 0, an infinite result error is produced. For positive real numbers, the result is a real but for negative real numbers, the result is complex.