The curves intersect at (0,0), (1,1)
Translate the x-axis to coincide x=-1 as the new X-axis:
x->X
y->Y-1
the curves change correspondingly:
y=x^2->Y=x^2+1
x=y^2->X=(Y-1)^2
=>the new intersecting points are (0,1), (1,2).
=>the volume of revolution is
........1
V=piS[(sqr(x)+1)^2-(x^2+1)^2]dx=
........0
...1
piS[x+2sqr(x)-x^4-2x^2]dx=
...0
......1
pi[(x^2)/2+4(x^1.5)/3-(x^5)/5-2(x^3)/3]
......0
=29pi/30
=3.04 approximately.
y= x^2
x=sqrt(y)
x= y^2
sqrt(y)=y^2
y=y^4
y^4-y=0
y^3(y-1)=0
y=0; y=1 (limits of integration)
Volume = pi Int ((sqrt(y)+1)^2 - (y^2+1)^2) dy
Volume = pi Int (-y^4-2y^2+y+2sqrt(y)) dy
= 29pi/30
http://www.wolframalpha.com/input/?i=graph+x%3Dy%5...
The "shells" method will be convenient. The intersections of the two curves are at (0,0) and (1,1).
Height of a shell = sqrt(x) - x^2.
Radius of a shell = x - (-1) or x+1.
Thickness of a shell = dx.
Volume of a single shell = 2*pi*R*H* dx
= 2*pi*[x^(3/2) - x^3 + sqrt(x) - x^2] dx.
Indefinite integral is
2*pi*[(2/5)x^(5/2) - (1/4)x^4 + (2/3)x^(3/2) - (1/3)x^3].
Plug in 1 and 0, you get
2*pi[24/60 - 15/60 + 40/60 - 20/60] = 29pi/30.
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Answers & Comments
The curves intersect at (0,0), (1,1)
Translate the x-axis to coincide x=-1 as the new X-axis:
x->X
y->Y-1
the curves change correspondingly:
y=x^2->Y=x^2+1
x=y^2->X=(Y-1)^2
=>the new intersecting points are (0,1), (1,2).
=>the volume of revolution is
........1
V=piS[(sqr(x)+1)^2-(x^2+1)^2]dx=
........0
...1
piS[x+2sqr(x)-x^4-2x^2]dx=
...0
......1
pi[(x^2)/2+4(x^1.5)/3-(x^5)/5-2(x^3)/3]
......0
=29pi/30
=3.04 approximately.
y= x^2
x=sqrt(y)
x= y^2
sqrt(y)=y^2
y=y^4
y^4-y=0
y^3(y-1)=0
y=0; y=1 (limits of integration)
Volume = pi Int ((sqrt(y)+1)^2 - (y^2+1)^2) dy
Volume = pi Int (-y^4-2y^2+y+2sqrt(y)) dy
= 29pi/30
http://www.wolframalpha.com/input/?i=graph+x%3Dy%5...
The "shells" method will be convenient. The intersections of the two curves are at (0,0) and (1,1).
Height of a shell = sqrt(x) - x^2.
Radius of a shell = x - (-1) or x+1.
Thickness of a shell = dx.
Volume of a single shell = 2*pi*R*H* dx
= 2*pi*[x^(3/2) - x^3 + sqrt(x) - x^2] dx.
Indefinite integral is
2*pi*[(2/5)x^(5/2) - (1/4)x^4 + (2/3)x^(3/2) - (1/3)x^3].
Plug in 1 and 0, you get
2*pi[24/60 - 15/60 + 40/60 - 20/60] = 29pi/30.