find the volume of revolution about the x-axis for the given function and interbal, f(x)=sqrt(cos(x)sin(x)), [0,pi/2].
p.s: v=integral of pi(cos(x)sin(x)) from 0 to pi/2, i integrated it using u sub., and got ((pi)/(2))(sin(x))^2, and i plug in x=pi/2 and x=0, however the answer came out different as when i did it with my calculator.. can someone explain to me what i did wrong?

Question

find the volume of revolution about the x-axis for the given function and interbal, f(x)=sqrt(cos(x)sin(x)), [0,pi/2]. 
p.s: v=integral of pi(cos(x)sin(x)) from 0 to pi/2, i integrated it using u sub., and got ((pi)/(2))(sin(x))^2, and i plug in x=pi/2 and x=0, however the answer came out different as when i did it with my calculator.. can someone explain to me what i did wrong?