b)
in terms of y we will use the washer method
wen we slice through the point y, we get a disk with radius √y
the area of this cross section is
A(y)=π(√y)2=πy
and the volume of the approximationg cylinder (a disk with thickness Δy)is
A(y)Δy=πyΔy
the soild lies betweek y=0 and y=1 so its volume is
V=
from 1 to 0 =π/2
a)
2π
.. this is using slicing.. x
2 which is the function is the height of the volume while 2π is the circumference and x is the radius
=
