parallel vectors qn (1 Viewer)

[Masaken]

I've found part (a) to be 5√10. How would you get started with part (b)? (Specifically, I don't understand what it means to be parallel to the x-axis and how to link the a and b components in the parallel vector to the ones given at the start of the qn)

 

[Hamburgler]

Parallel to X-axis means in the form of:
So for what x values is j=0?

 

[Masaken]

oh i get it tysm