Which one of the following statements about vitamins is most accurate

Provide. a. list.

The displacement function is given by : r = bt2i + ct3j meters
the velocity function is the derivative of the displacement:
v = r' = 2bti + 3ct2j meter / second

now, for    the velocity vector make an angle of 45.0∘ with the x- and y-axes, the i and j components have to be equal:
2bt = 3ct2 (now solve for t)
2bt = t (3ct)
either t = zero (rejected)
or t = 2b / 3c seconds (accepted)