Why is there a minus sign between i and j vector instead of a plus sign?

F(X, y, Z) = 8Xye I + yze k (a) Find the curl of the vector field. curl F = 2 X ze"i+ (8rye? - yze")j - 8xek (b) Find the divergence of the vector field. div F = 2 X y ( 8ez + ex ) Solution or Explanation i j k (a) curl F = V x F = a/ax a/dy a/az = (zex - 0)i - (yzex - 8xyez)j + (0 - 8xez)k 8xyez 0 yzex = zeXi + (8xyez - yzex)j - 8xelk (b) div F = V . F = a (8xyez) + a ax ay (0) + az (yzex) = 8ye? + 0+ yex = y(8ez + ex)