What is the velocity vector for a moving particle with a position vector r of t equals the components 2 over t, the natural log of t ?

Question

What is the velocity vector for a moving particle with a position vector  ?

A
B
C
D

Answer 1

r(t) = ( 2/t, lnt) to find v(t) take the derivative of r(t) this gives dr(t)/dt = d/dt(2/t, lnt) the derivative of 2/t = -2/t² using the quotient rule and the derivative of ln is 1/t so v(t) =(- 2/t² , 1/t) which is answer C.