Very simple log problem - I'm missing something.

[Zaent]

A=12^(1/5)
Log(A)=(1/5)Log(12)

The next part in the book says:

Log(A)=0.2158
A=1.644

I don't know how to do this without a calculator, and with a calculator I'm getting 1.24.

I'm doing e^0.2158

Can anyone please tell me where I'm going wrong here?Note: this isn't homework, just something I've come across

 

[bhillyard]

How old is the book? If old (pre 1980) then the expectation is that you have and use a set of log tables.

Also log(A) implies log to base 10 i.e. 10^.1258.
The standard notation for logs to base e is Ln(A).

 

[jedishrfu]

Your mistake is using e and not 10. Base e is used when doing stuff with natural logs ie ln() and 10 is used when doing base 10 logs.

Google can supplement a calculator if one isn't readily available.

The old fashioned way of solving log problems was to use precomputed log tables. Alternatively you could use the ll scales of a decitrig sliderule.

 

[Zaent]

Thank you both! I figured the book was old because it was asking me to do this, but I still knew my log knowledge was off somewhere. I'll remember the base 10 thing in future. Thanks again!