- #1
Sidthewall
- 33
- 0
1. Homework Statement
k so here is the equation i need help with that will find me the volume of a sphere
2*pi*y*sqrt(25-(y-1)^2) dy - 5*pi from 0 to 6
the 5 pi is the volume of a cylinder
2. Steps
so first i subbed u=y-1
took the 2 pi out of the integral
that got me 2 integrals u*sqrt(25-(u)^2) du + sqrt(25-(u)^2) du
the first integral = (2*pi*24^(3/2))/3
the second i used a trig sub and my final answer is
(25pi^2)/2 +
-25*asin(-.2)+sqrt(24)
3. Answer
the answer is suppose to be 25pi^2 + 500pi/3
i got 25pi^2 + (-75*asin(-.2)+3*sqrt(24)+2*(24)^(3/2) -15)/3
which is approx
25pi^2 + 499.89pi/3
how do i get the exact answer
k so here is the equation i need help with that will find me the volume of a sphere
2*pi*y*sqrt(25-(y-1)^2) dy - 5*pi from 0 to 6
the 5 pi is the volume of a cylinder
2. Steps
so first i subbed u=y-1
took the 2 pi out of the integral
that got me 2 integrals u*sqrt(25-(u)^2) du + sqrt(25-(u)^2) du
the first integral = (2*pi*24^(3/2))/3
the second i used a trig sub and my final answer is
(25pi^2)/2 +
-25*asin(-.2)+sqrt(24)
3. Answer
the answer is suppose to be 25pi^2 + 500pi/3
i got 25pi^2 + (-75*asin(-.2)+3*sqrt(24)+2*(24)^(3/2) -15)/3
which is approx
25pi^2 + 499.89pi/3
how do i get the exact answer