# Logarithms: ALG2 teacher say what?

1. May 13, 2008

### stephen92

I have these questions that are due tomorrow I am completely clueless on what my teacher is asking.

1. What is log(x), Explain.

I think that is like a parent function not sure

2.What is 10^log(10)

I know that it graphs as a straight line but thats it...

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Thanx,

Chris

Note: if the date May, 14 2008 has passed don't bother answering.

2. May 13, 2008

### symbolipoint

Study your textbook on the topics of exponential functions and logarithmic functions. They are inverses. Note carefully that 10^x is an exponential function. Its inverse is log(x), where the base is 10. One function will undo its inverse. This means that 10^(log(x))=x and that log(10^x)=x as long as the logarithm in these cases is 10.

3. May 25, 2008

### Trekky0623

1. log(x) is equal to the number that you must raise 10 to in order to get x. 10^(log(x)) = x. Logarithms are exponents.

2. log(10) = 1, since 10^1 = 10. So 10^(log(10)) = 10^1, or 10.

Last edited: May 25, 2008
4. May 28, 2008

### Nick89

Logarithms are not exponents! They are the inverse of exponents (huge difference!).

Basically, if $$y = \log_{a}(x)$$, then $$x = a^y$$

Just like, if $$y = x^2$$, then $$x = \pm \sqrt{y}$$

5. May 28, 2008

### HallsofIvy

Staff Emeritus
Nick89, logarithms are exponents.

They are the inverse of exponential functions and there is a huge difference between "exponential functions" and exponents.

As you say, if y= loga(x), then x= ay. y, the logarithm is an exponent!