Question about Texas Instruments TI-83 Plus Calculator

# I need help with a change of base formula problem.

Use the change of base formula to find the logarithm to four decimal places:log6.7(17). I'm not sure if thats how you would write it? anyone??

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It's simple here some logs:

log x base y = log x / log y
log (x*y) = log x + log y
log (x/y) = log x - log y
you just need to know that the default base of log in calculators is 10, so log x mean
log x base 10 = log x / log 10,
so write log x / log y for log x base y example:
log 8 base 2 = log 8 / log 2 that is how you write it on calculator, hope it was helpful

Posted on Jul 06, 2009

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• Contributor

The formula of the change of base is (log x)/(log b), where b is the base and x is the value you are trying to take the log of.

Posted on Jul 07, 2009

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Posted on Jan 02, 2017

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## Related Questions:

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To calculate the base 2 logarithm of 16, key in
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The same simple formula also works for any other base, and actually for any other logarithms provided by your calculator. The FX-300MS also provides a logarithm to base 10 (lg). You could also
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(from Wikipedia - the proof also follows if you want to go look it up)
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Hello,
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