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Mr Noblet
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Homework Statement
Let F=x[tex]^{2}[/tex]i+2xyj, and let C be the lower half of the unit circle, with perametrization r(t)=<cos(t),sin(t)>,[tex]\pi[/tex][tex]\leq[/tex]t[tex]\leq[/tex][tex]\pi[/tex]. Evaluate [tex]\oint[/tex]F[tex]\cdot[/tex]dr.
Homework Equations
The Attempt at a Solution
The first thing I tried to do was to find a function f(x,y) so that F=[tex]\nabla[/tex]f
In order to do this I integrated the i portion of F with respect to x which gave me f(x,y)=[tex]\frac{1}{3}[/tex]x[tex]^{3}[/tex]+g(y).
Then to find out what g was I took the derivative with respect to y which just left me with g'(y). I could not think of how to get past this part. I tried doing it with the j first as well in which I first take the integral of the j part of F with respect to y and then the derivative with respect to x. This left me with f[tex]_{x}[/tex](x,y)=y[tex]^{2}[/tex]+f'(x).
Basically I was trying to use the Fundamental Theorem of Line Integrals but I could not find a function f(x,y) so that F=[tex]\nabla[/tex]f. Help would be appreciated.
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