1. The problem statement, all variables and given/known data Consider the vector field F(r) = Φ^ (a) Calculate ∫ F⋅dl where C is a circle of radius R (oriented counterclockwise) in the xy-plane centered on the origin. 2. Relevant equations maybe Φ^ = -sinΦx^ + cosΦy^ 3. The attempt at a solution not really a solution. i am just stuck at what "dl" should be. if i go by my notes the "dl" is equal ∂l/∂θ (θ). but in our example its in terms of θ. so i dont know if "dl" here is equal to -sinΦx^ + cosΦy^. but can i evaluate the integral from 0 to 2π with Φ and not θ. thanks.