Question

Calc 3 help!

Suppose that Pi + Qj is parallel to the tangent vector of a closed curve C.
2 questions about this! Please help!

Answer 1

a) Show that Qi-Pj is perpendicular to the tangent vector.

b) Show that \[\int\limits_{}^{}\int\limits_{D}^{}(\delta P/\delta x + \delta Q/\delta y)dxdy = 0\] where D is the region whose boundary is C