Calculus 1 finding Unit Vector Position

Question

In the following r(t) is the position of an object as a function of time. Find a unit vector in the direction of travel at the given t

a) r(t) = (5t + cos(t), t sin(t), e^t), t = 0

Answer 1

if `vector r=(1,0,1) the unit vector is r/|r|.

in this case (1/√2,0,1/√2) since |r|=magnitude of r =√(r_x²+r_y²+r_z²)

of course, 1/√2=√2/2