how to take out the log of 13 * 10 power 6please explain properly
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The first step is to write this number in scientific notation. Thus, 13 X 106 will be written as 1.3 X 107. Next, we will take the log of the above number. Hence, we will have
log (1.3 X 107) = log 1.3 + log 107
[using log (ab) = log(a) + log(b)]
= log 1.3 + 7 log(10)
[using log(a)m = m X log(a)]
Since log 10 = 1, hence 7 log(10) will be
= 7 X 1 = 7
Now, we will look the up the log table to find the value of log 1.3. The value corresponding to 13 in the log table is 1139. So, it will be reported as
log 1.3 = 0.1139.
Thus, the value of log 1.3 + 7 log(10) is
= 0.1139 + 7 = 7.1139
Hence the value of log 1.3 is 7.1139.