volume using cross-sections

Calculus
Tutor: None Selected Time limit: 1 Day

find the volume of the solid generated by revolving the region about the y-axis. the region enclosed by x=y^2/3, x=0, y=-3,y=3....... i need every step.

May 20th, 2015

Here is the graph of the region

https://www.desmos.com/calculator/hnvlft8ofa

So the way I did it was since I know the graph is being rotated around the y-axis, I know that we are dealing with circles as cross sections. So now I need to know how much of each circle is contained in the region. So the region revolved to the y-axis is a quarter rotation, So the cross sections will be quarter circles. So now we have the integral from 3 to 0 of the equation 1/4pi(y^2/3)^2 dy. Put the 1/4pi on the other side for now and take the integral from 3 to 0 of y^4/9 dy, which is y^5/45 = 243/45 x 1/4pi. Since this is one eight of the total volume multiply this value by 8 to get 486pi/45. I hope this is right. Let me know if you have any questions.


May 20th, 2015

Did you know? You can earn $20 for every friend you invite to Studypool!
Click here to
Refer a Friend
...
May 20th, 2015
...
May 20th, 2015
Dec 6th, 2016
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer