(906, #9) Evaluate the line integral:

(906, #9) Evaluate the line integral

where C: x = 2t, y = 3sin(t), z = 3cos(t) , t = 0..Pi/2

Solution: First,

ds = sqrt(4+9 cos²(t) + 9 sin²(t) ) = sqrt(13)dt

Then

by C.A.H.