Show that the height of the cylinder of maximum volume that can be inscribed in a sphere of radius R is .
Let the radius, height and volume of cylinder be r, h and V respectively
Radius of sphere = R (Given)
Volume of cylinder, V = πr2h …1
OC = R
BC = r
In triangle OBC,
+ r2 = R2
r2 = R2 -
…2
Replacing equation 2 in equation 1, we get
V = π (R2 - )(h) = πR2h -
Condition for maxima and minima is
= 0
Since, h cannot be negative
Hence,
For < 0
V will be maximum for