1. A path of motion is given by a vector function r(t) = [4 cost, 4 sint, 31]. (0.4.). (a) Find the length of above vector from =(4,0,0) to = 0,4, Y (b) Find the tangential acceleration and the tangent of the curve as 60 degree rotation (from the initial of 0 degrees).

I need detailed help solving this exercise from homework of Engineering Mathematics II.
I do not really understand how to do, please do it step by step, not that long but clear. Thank you!

P.S.: Please do not use AI, thanks!