Wht does this sign mean?

1. Apr 12, 2012

brandy

($\frac{\partial z}{\partial x}$)y

the small y, what does it mean.
the context this is used in is F(x,y,z) where each variable is a function of the other 2 variables.

2. Apr 12, 2012

D H

Staff Emeritus
It means that y is to be deemed a constant while taking the partial of z with respect to x.