LN
Returns the natural logarithm of a number.
Synopsis
LN(number)
Arguments
number  An expression that resolves to a positive number. 
Description
The LN function returns the natural logarithm of number. The number value must be a nonzero positive number; all other values generate an <ILLEGAL VALUE> error.
The LN function complements the action of the EXP function, which is sometimes referred to as the antilogarithm.
Examples
The following example uses the LN function to calculate the natural logarithm of each of the integers 1 through 10:
FOR x=1 TO 10
PRINT "Natural log of ",x," = ",LN(x)
NEXT
See Also

EXP function