Why are my answers incorrect for 14a and 14b? Are they actually correct?(Sometimes it's the problem of this website.)

14. [1/3 Points] DETAILS PREVIOUS ANSWERS SCALCET8 12.2.042. MY NOTES | PRACTICE AI' (a) Find the unit vectors that are parallel to the tangent line to the curve y = 8 sin(x) at the point (77/6, 4). (Enter your answer as a comma-separated list of vectors.) (W Minx/W 4W) 17 7 17 17 ' 17 x (b) Find the unit vectors that are perpendicular to the tangent line. _4_; L_1_ (c) Sketch the curve y = 8 sin(x) and the vectors in parts (a) and (b), all starting at (It/6, 4). Y 10 WebAssign Plot