# Math Help - Line integral question needed for final exam

1. ## Line integral question needed for final exam

Compute line integral SC r x dr

where x2+y2=a2 and z=0 (Curve is circle with radius a)

I need it for tomorrow's final exam. Thanks.

2. Is that:

$\oint_C r \ dr$

where $C = \{x,y \: : \: x^2+y^2=a^2\}$ ?

Is that an integral in the complex plane, with $r=x+iy$? An integral in $\mathbb{R}^2$ with $r=(x,y)$ (which is essentially the same thing)? Or is $r$ some other function of $(x,y)$ such as the length?

I'm also not sure why you say "and z=0".

3. The curve is circle with radius -a- on xy plane.