The volume of the body of revolution is obtained when the plane figure enclosed by the line y = √ (x-1), x = 4 and y = 0 rotates around the x-axis Review is urgent,

The volume of the body of revolution is obtained when the plane figure enclosed by the line y = √ (x-1), x = 4 and y = 0 rotates around the x-axis Review is urgent,

Volume of a body of revolution = continuous sum (integral) of {base area π [√ (x-1)] & # 178; × height DX (differential element method)}
so
∫(1→4)π[√(x-1)]²dx
=∫(1→4)π(x-1)dx
=∫(1→4)(π/2)d(x-1)²
=(π/2)[(4-1)²-(1-1)²]
=9π/2