The volume of this solid can also be computed using cylindrical shells via an integral
2pi(x+4)(4x-x^2) dx
with limits of integration 0 and 4
volume is cubic units.
I am stuck on the last step. For some reason I tried integrating it and then plugging in the value, which in this case is just the beta, 4.
What am I doing wrong? this is supposed to be easy step..
Thanks!
I am trying it on the other problems but got stuck on this one..
integral of 2pi x^(1-6) from 0 to 7
I got -1/4 x^4. I plugged in the 7 to get 2pi-(1/(4* 7^4)) but that's a negative volume? I took off the negative sign but still not right... thanks