Respuesta :
Assuming that S is the end point.
No, I do not agree because you have to start with the endpoint.
No, I do not agree because you have to start with the endpoint.
In ray SR, S is the initial point and R is the terminal point.
In ray RS, these points are swapped. That is, the initial point is R while the terminal point is S.
So, ray RS is oppositely oriented to SR.
Hence, ray SR should not be called ray RS.
