Chapter 14.2, Problem 13E

Scalar line integrals with arc length as parameter Evaluate the following line integrals.

13.     ${\displaystyle \underset{C}{\int }\left(x^2-2y^2\right)ds;}$C is the line circle $r\left(s\right)=\left(s/\sqrt{2,}s/\sqrt{2}\right)$, for $0\le s\le 4$.