Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2007-06-05 13:24:10
- ruihan106
- Member
- Registered: 2007-05-30
- Posts: 7
Integration
Given the function
where a is a constant, . Let be the region bounded by , x-axis and y-axis. Let be the volume obtained when is rotated by about the y-axis. Given that find a.Last edited by ruihan106 (2007-06-05 14:20:40)
.9999999999 = 1
Offline
#2 2007-06-05 17:44:31
- George,Y
- Member
- Registered: 2006-03-12
- Posts: 1,379
Re: Integration
Draw the function, sketch the volume after rotation.
Slice the volume vertical to x axis and then integrate.
X'(y-Xβ)=0
Offline
#3 2007-06-05 17:45:38
- George,Y
- Member
- Registered: 2006-03-12
- Posts: 1,379
Re: Integration
Hint
f(x) passes (-a,0) (a,0) and (0,a[sup]2[/sup])
X'(y-Xβ)=0
Offline
#4 2007-06-05 19:10:07
- ruihan106
- Member
- Registered: 2007-05-30
- Posts: 7
Re: Integration
For
i got . For i got . The answer provided is. Can anyone check my answer. ThanksLast edited by ruihan106 (2007-06-05 19:11:50)
.9999999999 = 1
Offline
#5 2007-06-05 19:27:56
- George,Y
- Member
- Registered: 2006-03-12
- Posts: 1,379
Re: Integration
I got
X'(y-Xβ)=0
Offline
#6 2007-06-05 19:28:19
- George,Y
- Member
- Registered: 2006-03-12
- Posts: 1,379
Re: Integration
The same G.
X'(y-Xβ)=0
Offline
#7 2007-06-05 20:47:14
- JaneFairfax
- Member
- Registered: 2007-02-23
- Posts: 6,868
Re: Integration
For
i got . For i got . The answer provided is. Can anyone check my answer. Thanks
Your answer for V is wrong. You are rotating about the y-axis, not the x-axis; also, the answer should have a π in it.
Last edited by JaneFairfax (2007-06-06 02:26:24)
Offline
#8 2007-06-06 02:15:43
- ruihan106
- Member
- Registered: 2007-05-30
- Posts: 7
Re: Integration
OH.. Thanks a lot. I wrote it as
instead of . Careless mistake...Last edited by ruihan106 (2007-06-06 02:15:56)
.9999999999 = 1
Offline
#9 2007-06-06 02:27:15
- JaneFairfax
- Member
- Registered: 2007-02-23
- Posts: 6,868
Re: Integration
Glad you sorted out the problem now. 
Offline
#10 2007-06-06 02:42:42
- GANGADHARA.R
- Member
- Registered: 2007-06-06
- Posts: 1
Re: Integration
3 3 3 3 3 =100 Is My Problem Please Solve This By Addition Or Subtraction Or Division Or Multiplication In B/w Thees Numbers Finally I Want Iis The Answers
Offline
#11 2007-06-06 13:59:29
- ruihan106
- Member
- Registered: 2007-05-30
- Posts: 7
Re: Integration
Is it correct?
Last edited by ruihan106 (2007-06-06 14:05:45)
.9999999999 = 1
Offline
Pages: 1