# Math Help - logarithmic function

1. ## logarithmic function

y=log_10x, is the ____ of the exponential function, y=10x. is ____ a reciprocal, inverse, direct variation, or ratio?

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in a table were y varies inversely as x. how would you write an equation showing this variation?
x | 3 | 6 | 18
y | 3 | 3/2 | 1/2

2. Originally Posted by tyonna
y=log_10x, is the ____ of the exponential function, y=10x. is ____ a reciprocal, inverse, direct variation, or ratio?

$log_{10}(100) = 2$

$10^2 = 100$

what's happening?

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in a table were y varies inversely as x. how would you write an equation showing this variation?
x | 3 | 6 | 18
y | 3 | 3/2 | 1/2

the bold statement above translates to ... $y = \frac{k}{x}$ ... where k is a constant.
...

3. $y = kx$ stands for direct variation. $y = 10x$. Direct variation.

4. Originally Posted by A Beautiful Mind
$y = kx$ stands for direct variation. y= 10x. Direct variation.
The question is supposed to be $y = log_{10}x$ is the ________ of the exponential function, $y = 10^x$

5. Originally Posted by Defunkt
The question is supposed to be $y = log_{10}x$ is the ________ of the exponential function, $y = 10^x$
that's what i was trying to write i just don't know how to on a computer

6. 1) is the logarithmic form of the exponential function, .

2) y= k/x; k = xy = 3(3) = 9, then y = 9/x.

see plot of 1) y = 10^x and 2) y = 9/x