So basically you don't know how to evaluate: right? You have to use a trig identity.
integral of sine squared
So you should obtain
i big idiot i couldnīt count this task ....Could anyone help me please?
y = sinx
x = 0
x = π around the x axis
http://www.sdilej.eu/pics/9ee44f5f2f1c9 ... c915dc.jpg
outcome is 1/2 Π^2