1. The problem statement, all variables and given/known data Hi!, can anybody help me with this problem? Proof that the position vector r(t) = A cos [tex]\omega[/tex]t i + B sin ([tex]\omega[/tex]t + [tex]\alpha[/tex]) moves on an ellipse. I understand that the parametric equation for an ellipse is x=a cos t & y=b sin t, but I just can't find any trigonometric identity that helps me. Do you know any math trick that could help me?