JAMB - Mathematics (2000 - No. 27)
A bowl is designed by revolving completely the area enclosed by y = x2 - 1, y = 3 and x ≥ 0 around the y-axis. What is the volume of this bowl?
7π cubic units
15π/2 cubic units
8π cubic units
17π/2 cubic units
Explicació
∫30 π(y+1) dy = π[y2 + y30
= π(9/2 + 3) = 15π/2
= π(9/2 + 3) = 15π/2