3) Consider the vector field F =< sin y, x cos y, - sinz > a) With the help of a theorem, show that F is a conservative vector field. b) Find the work done in moving a particle in F from (1,0,0) to (0,-1,³pi/2)along the helix given by the position function r(t) =< cost, sint, t>, t€ [0,³pi/2]2