Homework Statement
the actual problem is to show that d(x,y)=d1(x,y)/[1+d1(x,y)] expresses a distance in R^n if d1(x,y) is a distance in R^n.Based on theory I have to show that
i) d(x,y)>=0 ,
ii)d(x,y)=d(y,x) and
iii)d(x,y)<= d(x,z)+d(z,y)
i've proven the first two so basically how can i...