Derivative of a Vector Function

1. The problem statement, all variables and given/known data



r(t) = ln ti + j, t > 0



find r′ (t) and r″(t)





2. Relevant equations



none



3. The attempt at a solution



r'(t)= 1/t i



am I on the right track? The answer in the back is r'(t)= 1/t i -1/t^2 j



Please help asap this is quite urgent! Thank you!