Find the unit tangent vector at the indicated point of the v

Find the unit tangent vector at the indicated point of the vector function r(t) = e^4t cos t i + e^4t sin t j + e^4t k

T(t) = r(t)/|r(t)|

r(t)= e^4t costi+e^4t Sintj+e^4t comparing with r(t)=xi+yj+zk

x=e^4tcost, dx/dt at t=/2,

dx/dt= 4e^4tcost-e^4tsint=-e^2

y=e^4tsint, dy/dt at t=/2,

dy/dt= 4e^4tsint+e^4tcost= 4e^2

z=e^4t, dz/dt at t=/2

dz/dt= 4.e^4t=4e^2

T(/2)= -e^2i+4e^2j+4e^2k/(-e^2)²+(4e^2)²+(4e^2)²

T(/2)= -e^2i+4e^2j+4e^2k/e^233 Ans.