SOLUTION: In general, how do I find the logarithm of the answer ex: evaluate 1776^53 I can get 53 Log 1776 = log x, but what is next?

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Question 167703This question is from textbook Algebra and Trigonometry
: In general, how do I find the logarithm of the answer
ex: evaluate 1776^53
I can get 53 Log 1776 = log x, but what is next?
This question is from textbook Algebra and Trigonometry

Found 2 solutions by stanbon, Edwin McCravy:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
1776^53
------------
Let x = 1776^53
log(x)= 53*log(1776)
log x = 53*3.24944...
---------------
10^(logx) = 10^(53*3.24944...)
x = 10^172.2203...
==================
Cheers,
Stan H.

Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
Edwin's solution follows:
In general, how do I find the logarithm of the answer
ex: evaluate 1776%5E53
I can get 53%2Alog%281776%29+=+log%28x%29, but what is next?

You could get your calculator and find log%281776%29 which is
3.249442961 and then mutiply that by 53 to get
172.220477. However that won't get you any closer
to finding 1776%5E53!

That's because calculators as a rule can only work 
directly with numbers less than 10%5E100, "1 google".

You can't get 1776%5E53 on a calculator directly because 
that number is bigger than googol. Most calculators made today 
can do anything but give an overflow error message for a google 
and anything larger.  

However you can get larger numbers indirectly on your calculator.

On my calculator I find that I can get 1776%5E30 
directly as matrix%281%2C3%2C3.042908149%2C+%22%D7%22%2C+10%5E97%29

However when I try to get 1776%5E31 I get an overflow
error message.  

We can break 1776%5E53 down this way:

1776%5E53=%281776%5E30%29%281776%5E23%29 both of which can be 
found on the calculator:

matrix%281%2C5%2C1776%5E30%2C+%22=%22%2C+3.042908149%2C+%22%D7%22%2C+10%5E97%29  
matrix%281%2C5%2C1776%5E23%2C+%22=%22%2C+5.459943055%2C+%22%D7%22%2C+10%5E74%29

Then we can multiply those decimal parts, matrix%281%2C5%2C3.042908149%2C+%22%D7%22%2C5.459943055%2C%22=%22%2C16.61410521%29++ 

then add the exponents of ten and get matrix%281%2C5%2C++10%5E97%2C+%22%D7%22%2C+10%5E74%2C+%22=%22%2C+10%5E171%29

So therefore

matrix%281%2C5%2C+1776%5E53%2C+%22=%22%2C+16.61410521%2C+%22%D7%22%2C+10%5E171%29

However, that's not in scientific notation because 16.61410521
is not less than 10, so we write it in scientific notation as
matrix%281%2C3+%2C1.661410521%2C+%22%D7%22%2C+10%5E1%29, then substituting we have



or adding the exponents of ten:

matrix%281%2C5%2C+1776%5E53%2C+%22=%22%2C+1.661410521%2C+%22%D7%22%2C+10%5E172%29

Notice that we could have broken 1776%5E53 down in a number
of other ways, for example:



so
.

And so we have, as above:

matrix%281%2C5%2C+1776%5E53%2C+%22=%22%2C+1.661410499%2C+%22%D7%22%2C+10%5E172%29

There is a slight difference between the two.  I would guess
that that latter is closer to the true value, but we could
safely round either answer to this: 

matrix%281%2C5%2C+1776%5E53%2C+%22=%22%2C+1.6614105%2C+%22%D7%22%2C+10%5E172%29

Edwin