The first force components:
Fx = ax + by², Fy = az + 2bxy, Fz = ay + bz²
I calculated the integral V=-∫Fdr, using dr=(dx,dy,dz)
The result I found was
The answer in the book (Kibble's Classical Mechanics): -(1/2(ax²)+azy+bxy²+1/3bz³)
The second force:
Fr = 2ar sin...