Let F:X x Y-> Z. We say that is continuous in each variable separately if for each y_0 in Y the may h: X-> Z defined by h(p)=F(p,y_0) is continuous and for each x_0 in X the map k:Y->Z defined by k(q)=F(x_0,q).Show that if F is continuous then F is continuous in each variable./
I couldn't understand the continuous in each variable part what does that mean??