- 7th June 2004, 10:36 #1

- Join Date
- Apr 2004
- Location
- Pakistan
- Posts
- 65
- Helped
- 0 / 0
- Points
- 1,798
- Level
- 9

## difference between log and log to the base 10

HI

can any one explain me difference between natural log and log of base ten.

Thanks

- 7th June 2004, 14:54 #2

- Join Date
- Jul 2002
- Location
- Middle Earth
- Posts
- 4,632
- Helped
- 476 / 476
- Points
- 37,801
- Level
- 47

## natural log of pi

A number can be represented by a first number raised to the exponent of a second number. The second number is call the logarithm and the first number is the base. The two most common bases are 10 and 2.7......

The symbol for the first is Log and for the second Ln.

- 7th June 2004, 14:54

- 7th June 2004, 21:15 #3

- Join Date
- Apr 2004
- Location
- between hell and heaven
- Posts
- 239
- Helped
- 9 / 9
- Points
- 3,886
- Level
- 14

## differnece between ln and log

the reson of choosing 10 is obvious, but why e=2.7...?

the answer is that it back to 300 years or more ago. to Euler (which e comes from his name). the function e^x is the only function that its derivative (and consequently its integral) is itself. {e^x'=e^x). no other function has this charasteristic. the number e could be achieved by several numerical and analytical methods, more often infinite summations.

this number has more important rule in complex analysis.

marti

- 7th June 2004, 21:15

- 10th June 2004, 12:52 #4

- Join Date
- Apr 2002
- Location
- USA
- Posts
- 3,944
- Helped
- 649 / 649
- Points
- 40,208
- Level
- 49

## difference between natural log and log of base ten

And if you need to convert between them:

log10(x) = ln(x) / ln(10)

ln(x) = log10(x) / log10(e)

- 10th June 2004, 12:52

- 10th June 2004, 13:12 #5

- Join Date
- May 2004
- Posts
- 38
- Helped
- 0 / 0
- Points
- 1,666
- Level
- 9

## Re: difference between natural log and log of base ten

y

y = log (x) ==>find y: x = b

b

where b is the base (b = 10 or b = e)

- 12th July 2004, 11:28 #6

- Join Date
- Jun 2004
- Posts
- 5
- Helped
- 0 / 0
- Points
- 1,613
- Level
- 9

## Re: difference between natural log and log of base ten

Thanks for your interesting reply. I did not realise the

**e**comes from Euler's name until I real your post!

By the way, does anybody know any history of the pi (3.14)?

Originally Posted by**mamali**

- 12th July 2004, 11:47 #7

- Join Date
- Mar 2002
- Posts
- 1,312
- Helped
- 56 / 56
- Points
- 21,367
- Level
- 35

## Re: difference between natural log and log of base ten

Originally Posted by**no**

http://www.wordiq.com/definition/Pi

http://www.campusprogram.com/referen...a/p/pi/pi.html

http://www.briantaylor.com/Pi.htm

There 100's of pages like this, no need to ask about it here.

- 4th December 2005, 03:02 #8

- Join Date
- Nov 2005
- Location
- Dominican Republic
- Posts
- 43
- Helped
- 4 / 4
- Points
- 1,511
- Level
- 8

## Re: difference between natural log and log of base ten

virology.wisc.edu/acp/Classes/ DropFolders/DropBioMod_lectures/M04-NatLogs.pdf

there u go

- 8th May 2006, 07:42 #9

- Join Date
- Feb 2006
- Posts
- 69
- Helped
- 6 / 6
- Points
- 1,690
- Level
- 9

## Re: difference between natural log and log of base ten

By the way, does anybody know any history of the pi (3.14)?

The ratio of circumference to diameter is pi.

Note that pi=22/7 is just an approximation,thats why it not a rational but irrational number

- 8th May 2006, 18:35 #10

- Join Date
- Oct 2005
- Posts
- 6
- Helped
- 1 / 1
- Points
- 1,385
- Level
- 8

## difference between natural log and log of base ten

You should read:

e: The Story of a Number

by Eli Moar

for a more historical and detailed discussion.