1] how to find the unit tangent vector T(t)at the indicated point of the vector function r(t)=(e^(8t) cos(t)) i + (e^(8t)sin(t)) j + (e^(8t)) k ,what is $\displaystyle T(pi/2) $ ?

>> i am not sure, but i kind of think that it should be derivative and divided by the magnitude.. but somehow it cannot be done, please help!!!

And also 2] how to find parametric equations for the tangent line at the point $\displaystyle (cos(3pi/6),sin(3pi/6),(3pi/6))$ on the curve $\displaystyle x = cos t, y = sin t ,z = t $?

>> i totally get lost from the question.. can someone please help? :)