LogarithmsDate: 12/2/95 at 11:57:31 From: Anonymous Subject: What are logarithems? Dr. Math, What is a logarithm? If you could please let me know that would be great. Date: 12/4/95 at 0:40:38 From: Doctor Ken Subject: Re: What are logarithems? Hello! Logarithms are really neat! Here's how they work. You know that 3^2 = 9, right (3^2 means three squared)? Well, here's another way you can write that: Log 9 = 2 3 What that's supposed to look like is a "Log" with a subscript of 3. The way you say that equation is "the log to the base 3 of 9 is 2." The way you think about it is this: the log to the base x of y is the number you can raise x to to get y. The log is the _exponent_. That's how I remembered logs the first time I saw them: I just kept repeating "the log is the exponent, the log is the exponent, ..." What I mean by that is that the log of some number is the exponent you have to raise the base to to get that number. So let's do another example: What's the log to the base 5 of 625? In other words, find the value of: Log 625. 5 Well, since 5^4 = 625, the log (to the base 5) of 625 is 4. What's the log to the base 2 of 1024? Here are a couple of rules that you can use when you're dealing with logs: Log (ab) = Log a + Log b x x x Log (a^b) = b Log a x x Enjoy! -Doctor Ken, The Geometry Forum |
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