What is the difference between ln and log?

[galaxymar]

I thought there was no difference between the two, but when i saw the multiple choice on the web link, it seems that there is.

http://www.mathpractice.umb.edu/Practic ... tion29.php

see this is how i did it

x+4=log and then solved it for x which should be x=logv-4

when i checked it though, the answer was x=lnv-4

 

[Deleted member 4993]

If the question had asked \:

Let v = 10^(x+4) and solve for x

then your answer would have been correct.

ln is short for 'log natural' - and it has a base value of 'e'.

Thus

ln(e) = 1

and

log(10) = 1

log - when it is not specified - is assumed to have a base of 10.

 

[pka]

I thought there was no difference between the two, but when i saw the multiple choice on the web link, it seems that there is.

That strictly depends upon the textbook one is using. Most publishers insist that the two are different. For them Log is the logarithm using base 10, whereas Ln is the logarithm using base e the so called natural logarithm. However, some calculus text books, for example by Gillman & McDowell, use Log as the logarithm base e. So the answer to the question in the link is either c or d depending upon the definition being used. I will say that the most likely answer is c because that is the usage most widely accepted.