Answer:
![A=\pi\displaystyle\biggr[\frac{16}{3}-2\ln(|3|)\biggr]\approx9.8524](https://tex.z-dn.net/?f=A%3D%5Cpi%5Cdisplaystyle%5Cbiggr%5B%5Cfrac%7B16%7D%7B3%7D-2%5Cln%28%7C3%7C%29%5Cbiggr%5D%5Capprox9.8524)
Step-by-step explanation:
Use the Washer Method
where
is the outer radius and
is the inner radius.
If we sketch out the graph, we see that
intersects points
and
, which will be our bounds of integration.
Here, our outer radius will be
and our inner radius will be
.
Thus, we can compute the integral and find the volume:
![A=\pi\displaystyle\int\limits^{3}_{1} {(-2)^2-\biggr(-1-\frac{1}{x}\biggr)^2 } \, dx\\ \\A=\pi\displaystyle\int\limits^{3}_{1} {4-\biggr(1+\frac{2}{x}+\frac{1}{x^2} \biggr) } \, dx\\\\A=\pi\displaystyle\int\limits^{3}_{1} {4-1-\frac{2}{x}-\frac{1}{x^2}} \, dx\\\\A=\pi\displaystyle\int\limits^{3}_{1} {3-\frac{2}{x}-\frac{1}{x^2}} \, dx\\\\A=\pi\displaystyle\biggr[3x-2\ln(|x|)+\frac{1}{x}\biggr]\Biggr|_{1}^{3}\\](https://tex.z-dn.net/?f=A%3D%5Cpi%5Cdisplaystyle%5Cint%5Climits%5E%7B3%7D_%7B1%7D%20%7B%28-2%29%5E2-%5Cbiggr%28-1-%5Cfrac%7B1%7D%7Bx%7D%5Cbiggr%29%5E2%20%7D%20%5C%2C%20dx%5C%5C%20%5C%5CA%3D%5Cpi%5Cdisplaystyle%5Cint%5Climits%5E%7B3%7D_%7B1%7D%20%7B4-%5Cbiggr%281%2B%5Cfrac%7B2%7D%7Bx%7D%2B%5Cfrac%7B1%7D%7Bx%5E2%7D%20%20%5Cbiggr%29%20%7D%20%5C%2C%20dx%5C%5C%5C%5CA%3D%5Cpi%5Cdisplaystyle%5Cint%5Climits%5E%7B3%7D_%7B1%7D%20%7B4-1-%5Cfrac%7B2%7D%7Bx%7D-%5Cfrac%7B1%7D%7Bx%5E2%7D%7D%20%5C%2C%20dx%5C%5C%5C%5CA%3D%5Cpi%5Cdisplaystyle%5Cint%5Climits%5E%7B3%7D_%7B1%7D%20%7B3-%5Cfrac%7B2%7D%7Bx%7D-%5Cfrac%7B1%7D%7Bx%5E2%7D%7D%20%5C%2C%20dx%5C%5C%5C%5CA%3D%5Cpi%5Cdisplaystyle%5Cbiggr%5B3x-2%5Cln%28%7Cx%7C%29%2B%5Cfrac%7B1%7D%7Bx%7D%5Cbiggr%5D%5CBiggr%7C_%7B1%7D%5E%7B3%7D%5C%5C)
![A=\pi\displaystyle\biggr[\biggr(3(3)-2\ln(|3|)+\frac{1}{3}\biggr)-\biggr(3(1)-2\ln(|1|)+\frac{1}{1}\biggr)\biggr]\\\\A=\pi\displaystyle\biggr[\biggr(9-2\ln(|3|)+\frac{1}{3}\biggr)-\biggr(3+1\biggr)\biggr]\\\\A=\pi\displaystyle\biggr[\biggr(\frac{28}{3}-2\ln(|3|)\biggr)-\biggr(4\biggr)\biggr]\\A=\pi\displaystyle\biggr[\frac{16}{3}-2\ln(|3|)\biggr]\\A\approx9.8524](https://tex.z-dn.net/?f=A%3D%5Cpi%5Cdisplaystyle%5Cbiggr%5B%5Cbiggr%283%283%29-2%5Cln%28%7C3%7C%29%2B%5Cfrac%7B1%7D%7B3%7D%5Cbiggr%29-%5Cbiggr%283%281%29-2%5Cln%28%7C1%7C%29%2B%5Cfrac%7B1%7D%7B1%7D%5Cbiggr%29%5Cbiggr%5D%5C%5C%5C%5CA%3D%5Cpi%5Cdisplaystyle%5Cbiggr%5B%5Cbiggr%289-2%5Cln%28%7C3%7C%29%2B%5Cfrac%7B1%7D%7B3%7D%5Cbiggr%29-%5Cbiggr%283%2B1%5Cbiggr%29%5Cbiggr%5D%5C%5C%5C%5CA%3D%5Cpi%5Cdisplaystyle%5Cbiggr%5B%5Cbiggr%28%5Cfrac%7B28%7D%7B3%7D-2%5Cln%28%7C3%7C%29%5Cbiggr%29-%5Cbiggr%284%5Cbiggr%29%5Cbiggr%5D%5C%5CA%3D%5Cpi%5Cdisplaystyle%5Cbiggr%5B%5Cfrac%7B16%7D%7B3%7D-2%5Cln%28%7C3%7C%29%5Cbiggr%5D%5C%5CA%5Capprox9.8524)
In conclusion, the volume of the solid of revolution will be about 9.8524 cubic units. See the attached graph for a helpful visual!
Y - y₁ = m(x - x₁)
y - 6 = 7(x - (-4))
y - 6 = 7(x + 4)
y - 6 = 7(x) + 7(4)
y - 6 = 7x + 28
<u> + 6 + 6</u>
y = 7x + 34
Let m represent the number of miles this guy runs in a day.
He runs every day, so the minimum number of miles has to be greater than 0.
According to the problem statement, the max number of miles is 3.5 miles or less.
Translate this into a (symbolic) inequality.