Tom,

You never cease to amaze me with your capabilities.

Alan


"Tom Ogilvy" wrote in message
...
LN is called the natural logarithm. It is a logarithm using the
exponential constant (2.718. . .) as the base (see below)

the arguments for log are


LOG(number,base)

Base is optional and if left out, defaults to base 10

so Log(10,10) = 1
Log(10) = 1

but
Log(3) is Log(3,10), not base 3 and equals 0.477121254719662
Log(3,3) = 1 is the logarithm of 3 using base 3.

like wise

EXP(1) gives the exponential consant - it is the exponential constant
raised to the 1st power
http://www.mathcentre.ac.uk/students...s/resources/41

=EXP(1) = 2.71828182845905 (not 2.3)

so
=LOG(EXP(1),EXP(1)) is 1
as is
=LN(exp(1))

so LN is equal to LOG with a base of exp(1), or the match constant e


--
Regards,
Tom Ogilvy


"Joel" wrote in message
...
ln IS A FUNCTION IN EXCEL

Log is usually referes to base 10
Log(10) = 1
Log(100) = 2
Log( 1000) = 3

If we did Log for base 3
Log(3) = 1
Log(9) = 2
Log(27) = 3

LN is the Log using e as the base where e equals approximately 2.3

"dr chuck" wrote:

This is a log trendline formula from Excel semilog graphing.

y = 0.8065Ln(x) + 3.4412

can anyone tell me how the " 0.8065Ln(x) " part of this formula works?

I know y and i am solving for "x"

not sure the significance of the "Ln"

do i have to use some "log" function?

--
dr chuck