Originally Posted by
TheEmptySet I was a bit careless with notation
These are Vectors and the dot means the dot product
$\displaystyle \int_{0}^{\pi} (2t\cos(t),\cos(t)+\cos(\cos(t)))\cdot (1,-\sin(t))dt$
$\displaystyle
\int_{0}^{\pi} 2t\cos(t)\vec i+ [\cos(t)+\cos(\cos(t)]\vec j)\cdot (\vec i,-\sin(t)\vec j)dt
$
Then this gives the bottome integral in the post before
What I said was: $\displaystyle F(x,y) = (2xy)i + (x^2 + cosy)j => (2tcost)i + (t^2 + cos(cost))j$ What did you do with $\displaystyle x^2$ ?