4.3 Logarithmic functions  (Page 6/9)

${\log }_{15}\left(a\right)=b$

${\log }_y\left(137\right)=x$

${\log }_{13}\left(142\right)=a$

$\text{log}(v)=t$

$\text{ln}(w)=n$

$4^x=y$

$c^d=k$

$m^{-7}=n$

${19}^x=y$

$x^{-\frac{10}{13}}=y$

$n^4=103$

${\left(\frac{7}{5}\right)}^m=n$

$y^x=\frac{39}{100}$

${10}^a=b$

$e^k=h$

${\text{log}}_3(x)=2$

${\text{log}}_2(x)=-3$

${\text{log}}_5(x)=2$

${\log }_3\left(x\right)=3$

${\text{log}}_2(x)=6$

${\text{log}}_9(x)=\frac{1}{2}$

${\text{log}}_{18}(x)=2$

${\log }_6\left(x\right)=-3$

$\text{log}(x)=3$

$\text{ln}(x)=2$

$\text{log}({100}^8)$

${10}^{\text{log}(32)}$

$2\text{log}(.0001)$

$e^{\ln \left(1.06\right)}$

$\ln \left(e^{-5.03}\right)$

$e^{\ln \left(10.125\right)}+4$

${\text{log}}_3\left(\frac{1}{27}\right)$

${\text{log}}_6(\sqrt{6})$

${\text{log}}_2\left(\frac{1}{8}\right)+4$

$6{\text{log}}_8(4)$

$\text{log}(10,000)$

$\text{log}(0.001)$

$\text{log}(1)+7$

$2\text{log}({100}^{-3})$

$\text{ln}(e^{\frac{1}{3}})$

$\text{ln}(1)$

$\text{ln}(e^{-0.225})-3$

$25\text{ln}(e^{\frac{2}{5}})$

$\text{log}(0.04)$

$\text{ln}(15)$

$\text{ln}\left(\frac{4}{5}\right)$

$\text{log}(\sqrt{2})$

$\text{ln}(\sqrt{2})$

Is $x=0$ in the domain of the function $f(x)=\log (x)?$ If so, what is the value of the function when $x=0?$ Verify the result.

Is $f(x)=0$ in the range of the function $f(x)=\log (x)?$ If so, for what value of $x?$ Verify the result.

Is there a number $x$ such that $\ln x=2?$ If so, what is that number? Verify the result.

Is the following true: $\frac{{\log }_3(27)}{{\log }_4\left(\frac{1}{64}\right)}=\mathrm{-1}?$ Verify the result.

Is the following true: $\frac{\ln \left(e^{1.725}\right)}{\ln \left(1\right)}=1.725?$ Verify the result.

The exposure index $EI$ for a 35 millimeter camera is a measurement of the amount of light that hits the film. It is determined by the equation $EI={\log }_2\left(\frac{f^2}{t}\right),$ where $f$ is the “f-stop” setting on the camera, and $t$ is the exposure time in seconds. Suppose the f-stop setting is $8$ and the desired exposure time is $2$ seconds. What will the resulting exposure index be?

Refer to the previous exercise. Suppose the light meter on a camera indicates an $EI$ of $-2,$ and the desired exposure time is 16 seconds. What should the f-stop setting be?

The intensity levels I of two earthquakes measured on a seismograph can be compared by the formula $\log \frac{I_1}{I_2}=M_1-M_2$ where $M$ is the magnitude given by the Richter Scale. In August 2009, an earthquake of magnitude 6.1 hit Honshu, Japan. In March 2011, that same region experienced yet another, more devastating earthquake, this time with a magnitude of 9.0. http://earthquake.usgs.gov/earthquakes/world/historical.php. Accessed 3/4/2014. How many times greater was the intensity of the 2011 earthquake? Round to the nearest whole number.