Math Is Fun Forum

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Calculator Exponentials if you have the exponent on the screen

Say you've been fiddling with numbers on your
calculator for a few seconds, and come up with
a long number...
Say you have a result of  .3319793322 on your
old-fashioned calulator, and
you want to know what 2^.331979332 is without
using your memory/recall keys or without retyping the
number in.  How do you do it?
You do inverse log of the .3319793322
Then raise that answer the power of
pressing "2 but take log of 2", then press equals.

inverselog(.3319793322)^(log(2))

is the same as
2^0.3319793322

I don't know why, but it works!

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igloo myrtilles fourmis

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Calculator Exponentials if you have the exponent on the screen

Here's why it works:

inverselog(x)^(log(2))
(10^x)^(log(2))
10^(xlog(2))
10^log(2^x)
2^x

You can also replace 2 with any other number.

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Why did the vector cross the road?
It wanted to be normal.