1. The problem statement, all variables and given/known data r(u,v)=u i +v j +(1/2)v k 2. Relevant equations 3. The attempt at a solution x=u : y=v : z=(1/2)v because x=u and y=v, x & y are the parameters so r(x,y)=x+y+(1/2)y=x+(3/2)y but the answer says it is y-2z=0. What am I not seeing correctly?