Hello,
This is a rather trivial problem. However I am missing something it appears.
x=sint, y=sin2t; 0<=t<=pi/2
i need to find volume. I am writing this from my phone, so this will not be pretty. But basically it's pi multiplied by the integral (limit 0 to pi/2) of (sin2t)^2 * cost dt
i rewrite squared sin in terms of cos > (1-cos4t)/2
i then have pi/2 * integral of (cost-cos4t*cost)
i rewrite cos4t*cost as cos5t + cos3t
and then it's quite obvious: (17/30)*pi
the answer in the book is (8/15)*pi. So it appears as if though I must have gotten (16/30)*pi
sorry for the mess. Again, I used my phone. Thank you for your help
This is a rather trivial problem. However I am missing something it appears.
x=sint, y=sin2t; 0<=t<=pi/2
i need to find volume. I am writing this from my phone, so this will not be pretty. But basically it's pi multiplied by the integral (limit 0 to pi/2) of (sin2t)^2 * cost dt
i rewrite squared sin in terms of cos > (1-cos4t)/2
i then have pi/2 * integral of (cost-cos4t*cost)
i rewrite cos4t*cost as cos5t + cos3t
and then it's quite obvious: (17/30)*pi
the answer in the book is (8/15)*pi. So it appears as if though I must have gotten (16/30)*pi
sorry for the mess. Again, I used my phone. Thank you for your help