(a) find the unit vectors that are parallel to the tangent line to the curve y = 8 sin x at the point (π/6, 4)
(b) find the unit vectors that are perpendicular to the tangent line.

So the following are the answer of your questions and i hope this will help to your study and your assignments:
a.(sqrt(13)/13, 2sqrt(39)/13)
b.(2sqrt(39)/13. -sqrt(13)/13)
I hope you understand my answer and feel free to ask for more clarification and questions. Have a nice day