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Solve for the value of log 81 without using calculatorShow the steps on how to solve it...

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spock4 | Student, Undergraduate | Honors

Posted May 16, 2012 at 6:27 AM via web

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Solve for the value of log 81 without using calculator

Show the steps on how to solve it (using table)

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thilina-g | College Teacher | (Level 1) Educator

Posted May 16, 2012 at 9:34 AM (Answer #1)

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Assuming you are using the base of 10 in the log, I will refer to the log10 table.

`log 81 = log 3^4`

But according to logarithm laws, we know,

`log 3^4 = 4log3`

Therefore,

`log81 = 4log3`

We can refer to log10 table for log3.

`log 3 = 0.4771` (according to table)

Then,

`log81 = 4(0.4771)`

`log81 = 1.9084`

 

The answer is 1.9084.

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