# Math Help - cylindrical polar coords

1. ## cylindrical polar coords

when trying to use green's theorem and i parametrise x,y and z using cylindrical polar coordinates, where x= Rcos (delta) y=Rsin(delta) z=z,

does the unit normal vector become cos(delta) i + sin(delta) j?

i thought it should be Rcos (delta) i + Rsin(delta) j but my formula list says otherwise.

2. Originally Posted by alexandrabel90
when trying to use green's theorem and i parametrise x,y and z using cylindrical polar coordinates, where x= Rcos (delta) y=Rsin(delta) z=z,

does the unit normal vector become cos(delta) i + sin(delta) j?
yes.

i thought it should be Rcos (delta) i + Rsin(delta) j but my formula list says otherwise.
Well, except if R=1, this is not a unit vector: it has length R.