On the line from (0, 1) to (0, 0), xisidentically 0. And on the line from (0, 0) to , y is identically 0. You could, for example, take as parametric equations for (0, 1) to (0, 0), x= 0, y= t with t from 1 to 0 and for (0, 0) to , x= t, y= 0 for t from 0 to .

I know it's going to be something obvious but I'd appreciate it if someone could help me out with this.

Thanks in advance

Craig