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chingching
Joined: 17 Nov 2004Posts: 7

Posted: Thu Nov 18, 2004 8:16 pm Post subject: an integal problem



how to slove this problem? find the volume of the solid generated by revolving the reigon bounded by y=x^2 and y=8x about the yaxis by the shell method.
it is the book question. who can teach me to slove it~~”





Wilson
Frequent VisitorJoined: 20 Oct 2004Posts: 74

Posted: Fri Nov 19, 2004 2:15 pm Post subject: Re: an integal problem



Let Put f(x) = 0, we have roots 0 and 8. The required volume
Actually, there is another method as follow: The require volume





Chan Pak Keung
Joined: 09 May 2004Posts: 16

Posted: Sat Nov 20, 2004 11:37 pm Post subject:



I am sorry to tell you that your question is not “Advanced Maths”, so
please post it on “High School Maths” next time.





chingching
Joined: 17 Nov 2004Posts: 7

Posted: Mon Nov 22, 2004 7:09 pm Post subject: thx



thx at first but it is very sorry that no one can answer this question in high
sch. maths……





chingching
Joined: 17 Nov 2004Posts: 7

Posted: Mon Nov 22, 2004 7:19 pm Post subject: a difficult thing



but why my bk. can make the ans. be 24*(pi)/5?





victorcheng
Joined: 16 Mar 2004Posts: 11

Posted: Thu Dec 09, 2004 4:30 pm Post subject: Re: a difficult thing



chingching wrote:

but why my bk. can make the ans. be
24*(
pi)/5?

i think if the answer in the book is correct, the second function should be y^2=8x





