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    Question: Name:  ImageUploadedByStudent Room1422196902.974176.jpg
Views: 84
Size:  48.7 KB

    Answer: Attachment 358543

    Problem: They have no substituted values into... Name:  ImageUploadedByStudent Room1422196943.108995.jpg
Views: 69
Size:  2.1 KB They've only substituted values into the integral of cos^5 x
    Why is this?

    Also what is the need to let y = sint and make the expression in terms of y? Is it to get the "exact answer"?


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    (Original post by ps1265A)
    Question: Name:  ImageUploadedByStudent Room1422196902.974176.jpg
Views: 84
Size:  48.7 KB

    Answer: Attachment 358543

    Problem: They have no substituted values into... Name:  ImageUploadedByStudent Room1422196943.108995.jpg
Views: 69
Size:  2.1 KB They've only substituted values into the integral of cos^5 x
    Why is this?

    Also what is the need to let y = sint and make the expression in terms of y? Is it to get the "exact answer"?


    Posted from TSR Mobile
    I can't follow what you're saying and your attachment isn't very clear either! I assume you're talking about the volume part of the question.

    Do you have a standard formula for a volume integral when using parametric coordinates?

    Do you agree with the integral that they write down in the first place?
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    Pi[Integral[(y^2)(dx/dT)dT] is what you are looking for in part b

    Which ultimately comes down to the integral of sin^2(2t)•cos(t)dt in which I suggest you manipulate sin(2t)=2cos(t)sin(t) then use a substitution on the integral
 
 
 
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