Step 1:

The integral is and is the right half of the circle.

Definition of the line integral :

If F is a continuous vector field on a smooth curve C, the function in the interval .

Then the line integral of F on C is .

The unit circle can be parameterized of the equation are and .

Since the right half of the circle, integrate the function in the interval .

Then .

Step 2:

The line integral of is

Consider .

Then the limits of integration will change from to

Substitute and in the above integral.

Solution :

.