Find the unit tangent vector T(t) at the point with the given value of the parameter t.r(t) =(t- 3t, 1 + 4t,1/3 t^3+1/2 t^2) ,t

Find the unit tangent vector T(t) at the point with the given value of the parameter t.r(t) =(t²- 3t, 1 + 4t,1/3 t^3+1/2 t^2) ,t = 3T(3)=