Calculus
posted by Liz on .
Find the volume of the solid of revolution by roating the region R about the yaxis. Write the answer as a multiple of pi.
y= sqrt(x), y=x^2, in the first Quadrant

The curves intersect at (0,0) and (1,1).
Using shells,
v = ∫2πrh dx [0,1]
where r = x and h=√xx^2
v = 2π∫x(√xx^2) dx [0,1]
= 3π/10
Using discs,
v = ∫π(R^2r^2) dy [0,1]
where R=√y and r=y^2
v = π∫(yy^4) dy [0,1]
= 3π/10