I tried that,
then R(t) = t i - t2j + t2k
R'(t) = i - 2t j + 2t k
and at given point P(1,-1,1) from equation of R(t) I get t = 1
So R'(1) = i - 2j + 2k , which is also velocity
But then speed, ||R'(1)|| = sqrt{1 + 4 + 4} = 3.. And according to the problem description, it should...