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### Solving a Logarithm

```
Date: 6/29/96 at 1:10:28
From: Anonymous
Subject: Solving a Logarithm

Hi! How are you?

I need help. Can you help me solve this question?

log a = -1.3
```

```
Date: 6/30/96 at 15:44:48
From: Doctor Luis
Subject: Re: Solving a Logarithm

In order to answer this question, you have to understand the
definition of a logarithm:

log(base p) q = r  if and only if  p ^ r = q.
[read p ^ r as "p raised to r-th power]

In other words, the logarithm represents the power to which
you need to raise the base to in order to give you the number
in front.

example:  log(base 2) 32 = 5 ( why?  because 2 ^ 5 = 32 )

Since you did not specify a base, by default it's 10 (some authors
take "e" as the default base)

Now you can write

log(base 10) a = -1.3

in the equivalent exponential form by using the definition
provided above, thus giving you the value of a.

-Doctor Luis,  The Math Forum
Check out our web site!  http://mathforum.org/dr.math/
```
Associated Topics:
High School Calculus

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