Volume of revolution integration for inverse sign

JNC

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Sep 7, 2020
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V = pi ∫ (2sin^-1(2/(y+2))+pi)^2 dy

Can't solve this for 360 degree revolution with respect to y axis... limits are from y = 0 to y = 5... is it solvable ?
 
original equation is y = 2cosec(x/2+pi/2) - 2
which I have been instructed to revolve around the y-axis 360 degrees to find volume between the limits 0 and 5
When rearranged in terms of x, i got:

X = 2[sin^-1(2/(y+2))+pi/2]
= 2sin^-1(2/(y+2))+pi
To find volume it is pi ∫ x^2dy from limits 0 to 5
= pi ∫ (2sin^-1(2/(y+2))+pi)^2 dy

What I have done is expanded it and then integrated the individual parts of the integral by integration by parts... however I used substitution and put t = 2(y+2) to simplify... but it is quite difficult... not sure if it is intergratable
 
original equation is y = 2cosec(x/2+pi/2) - 2
which I have been instructed to revolve around the y-axis 360 degrees to find volume between the limits 0 and 5
When rearranged in terms of x, i got:

X = 2[sin^-1(2/(y+2))+pi/2]
= 2sin^-1(2/(y+2))+pi
To find volume it is pi ∫ x^2dy from limits 0 to 5
= pi ∫ (2sin^-1(2/(y+2))+pi)^2 dy

What I have done is expanded it and then integrated the individual parts of the integral by integration by parts... however I used substitution and put t = 2(y+2) to simplify... but it is quite difficult... not sure if it is intergratable
The problem - as posted - will not converge to a finite volume.

Please post the EXACT problem as it was given to you.
 
there is no easy way to solve this integral by hand. you need to use complex analysis, and it is a very long solution

the better way to get the answer is just by using your calculator
 
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