Log Check

jonboy

Full Member
Joined
Jun 8, 2006
Messages
547
Hi guys hope your weekend is going great! :D

Now if you can check these problems and offer me some tips, you can make mine. ;)

2)\(\displaystyle \L \;log_{\frac{1}{8}}\frac{1}{16}\,=\,x\)

I've tried putting it into exponential form, getting:\(\displaystyle \L \;(\frac{1}{2^3})^{x}\,=\,\frac{1}{2^4}\)

So I solved\(\displaystyle \L \;3x\,=\,4\,to\,x\,=\,\frac{4}{3}\) but it don't work.

3) \(\displaystyle \L \;M\,=\,\frac{2}{3}\,log\frac{E}{10^{11.8}}\)

M = 6.6, Find E:\(\displaystyle \L \;6.6\,=\,\frac{2}{3}\,log\frac{E}{10^{11.8}}\)

Multiply be 3/2:\(\displaystyle \L \;9.9\,=\,log\frac{E}{10^{11.8}}\)

Raise to the 10 base:\(\displaystyle \L \;10^{9.9}\,=\,\frac{E}{10^{11.8}}\)

\(\displaystyle \L \;E\,=\,10^{21.7}\)

4) Same formula, E = 3.98 x 10<sup>22</sup>, solve for M:\(\displaystyle \L \;M\,=\,\frac{2}{3}\,log\frac{3.98\,\cdot\,10^{21.7}}{10^{11.8}}\)

With my calc I got \(\displaystyle \L \;M\,\approx\,7.2\)
 
You have a lot of errors.
\(\displaystyle \L\begin{array}{rcl}
2 - \ln (x - 2) & = & \ln (3) \\
2 & = & \ln (x - 2) + \ln (3) \\
2 & = & \ln (3x - 6) \\
e^2 & = & 3x - 6 \\
\end{array}.\)
 
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