I have this line integral:
$\oint 3ydx+x^2dy$
and the path is a line from $(0, 0)$ to $(1, 0)$ (so this is $y=0$), another line from $(1, 0)$ to $(1, 1)$ (so this is $x=1$) and a curve $y=x^2$ from $(1, 1)$ to $(0, 0)$.
Evaluating this integral using the line integral (and anticlockwise = positive):
1) $y=0$ gives $0$
2) $x=1$ gives $0$ as well
Edit: this gives actually $1$
3) $y=x^2$
$dy=2xdx$ and substituing everything in gives $\oint 3x^2dx+x^2*2xdx=\oint 3x^2+2x^3dx$. The limits are from $1$ to $0$, so $\int_1^0 3x^2+2x^3dx=-1.5$
Adding everything gives $-1.5$
Edit: This becomes actually $-0.5$
Now using Green's theorem: Finding the partial derivatives and substituing these into the Green's formula gives: $\int_0^1\int_0^{x^2}(2x-3)dydx=-0.5$
What am I doing wrong because obviously $-0.5 \neq -1.5$? Edit: $-0.5 = -0.5$
Thanks!