ok i got alright at the limits with two variables (to an extent haha)
but now i have this limit:
lim (x,y,z) --> (0,0,0) of (2(x^2)ycos(z))/(x^2 + y^2)
where do i start?
The variable z is only in the term $\displaystyle \cos z$ that is equal to 1 for z=0, so that the 'real' limit is...
$\displaystyle \displaystyle \lim_{(x,y) \rightarrow (0,0)} \frac{2\ x^{2}\ y}{x^{2} + y^{2}}$
Kind regards
$\displaystyle \chi$ $\displaystyle \sigma$