JEE Main20198 Apr 2019Evening ShiftMathematicsApplication of DerivativesActual
The height of a right circular cylinder of maximum volume inscribed in a sphere of radius 3 is:
Options
- A3
- B2 3 3
- C6
- D2 3
Correct answer
D. 2 3
Step-by-step solution
From the diagram, we get radius of cylinder = R 2 - h 2 2 ⇒ Volume of cylinder V = π R 2 - h 2 4 h For maximum volume: d V d h = 0 ⇒ π R 2 - 3 h 2 4 = 0 ⇒ h 2 = 4 R 2 3 = 4 × 9 3 = 12 ⇒ h = 2 3