Friday

November 28, 2014

November 28, 2014

Posted by **sara** on Sunday, August 3, 2014 at 6:47pm.

- math -
**Steve**, Sunday, August 3, 2014 at 7:00pmusing discs, of thickness dx

v = ∫[-1,1] πr^2 dx

where r = y = 1-x^2

So,

v = π∫[-1,1] (1-x^2)^2 dx = 16/15 π

Using shells, of thickness dy, we have to account for the two branches of the parabola, so it's easier just to use symmetry and get

v = 2∫[0,1] 2πrh dy

where r = y and h = x = √(1-y)

v = 4π∫[0,1] y√(1-y) dy = 16/15 π

- math -
**Damon**, Sunday, August 3, 2014 at 7:04pmpi y^2 dx from -1 to +1

same as 2 pi y^2 dx from 0 to 1

2 pi (1-2 x^2 + x^4) dx from 0 to 1

2 pi (1-0) - 4 pi (1^3/3-0) + 2 pi (1^5/5-0)

2 pi - 4 pi/3 + 2 pi/5

(pi/15) ( 30 - 20 + 6)

(16/15) pi

Check my arithmetic !

**Answer this Question**

**Related Questions**

Calculus - This problem set is ridiculously hard. I know how to find the volume ...

Calculus volume stuff - Find the volume of the solid obtained by rotating the ...

Calculus - solid is formed by rotating the region bounded by the curve y=e−...

Calculus - solid is formed by rotating the region bounded by the curve y=e&#...

Calculus - A solid is formed by rotating the region bounded by the curve y=e&#...

CALCULUS MAJOR HELP!!!!!! - Find the volume of the solid obtained by rotating ...

Calculus - a) Find the volume formed by rotating the region enclosed by x = 6y ...

Calculus [Finding volume of solid] - Find the volume of the solid formed by ...

calculus 2 - Find the volume of the solid formed by rotating the region ...

Calculus - 1. Find the volume formed by rotating the region enclosed by x=5y and...