(a) Show that $I=\int_{C}\left(x^{2} y d x+2 x y^{2} d y\right)$ is path dependent in the xy-plane
(b) Integrate from (0,0) along the straight-line segment to $(1, b), 0 \leq b \leq 1,$ and then vertically up to (1, 1): see the figure. For which of these paths is 1 maxirmum? What is its maximum value?
(c) Integrate from (0,0) along the straight-line segment to $(c, 1), 0 \leq c \leq 1,$ and then horizontally to $(1,1),$ For $c=1,$ do you get the same value as for $b=1$ in (b)? For which $c$ is $I$ maximum? What is its maximum value?