Respuesta :
Answer:
[tex]\frac{784}{15} \pi[/tex]
Step-by-step explanation:
According to the given situation, the calculation of volume of the solid is shown below:-
Here we will consider the curves that is
[tex]x = 7y^2, x = 7[/tex]
Now, rotating the line for the line x which is equals to 7
[tex]7y^2 = 7\\\\y^2 = 1\\\\ y = \pm1[/tex]
So, the inner radio is
7 - 7 = 0
and the outer radius is
[tex]7y^2 - 7\\\\ = 7(y^2 - 1)[/tex]
Now, the area of cross section is
[tex]A(y) = \pi(7(y^2 - 1))^2\\\\ = 49\pi(y^4 - 2y^2 + 1)[/tex]
The volume is
[tex]V = \int\limits^1_{-1} A(y)dy[/tex]
now we will put the values into the above formula
[tex]= \int\limits^1_{-1} 49\pi(y^4 - 2y^2 + 1)dy\\\\ = 49\pi(\frac{y^5}{5} - \frac{2y^3}{3} + y)^{-1}\\\\ = 49\pi(\frac{1}{5} - \frac{2}{3} + 1 + \frac{1}{5} - \frac{2}{3} + 1)\\\\ = 49\pi(2 + \frac{2}{5} - \frac{4}{3} )\\\\ = 49\pi(\frac{30+6-20}{15} )\\\\ = \frac{49\pi}{15} (16)[/tex]
After solving the above equation we will get
[tex]= \frac{784}{15} \pi[/tex]
