
evaluate the integral
Let C be the semi circle on the surface from to which passes through the point ( , , ) (note that x=y for all (x,y,z) on C.)
Evaluate the integral
(Suggestion: use as your parameter the angle Q subtended at the orgin by the arc NP for a point P on C)
I think i need to sketch the picture to understand it, but Im having a hard time to do it, is there another way to find x,y,z in term of t?

Your semi circle is part of the intersection between the plane x=y and the sphere of radius 2.
So points on your semicircle satisfy
Can you find parametric equations for x, y, and z on the semicircle?
Hint: x = y = Asin(t), z = Bcos(t), what are A,B, and the range for t?