2 2 2*(c - d)*(c + d) - (c - d) + 4*d
2*(c - d)*(c + d) - (c - d)^2 + 4*d^2
1*(c + d)
2 2 c + d + 2*c*d
c^2 + d^2 + 2*c*d
2 (c + d)
(c + d)^2
-(c - d)^2 + 4.0*d^2 + 2.0*(c + d)*(c - d)
2 2 2 - (c - d) + 2*c + 2*d
-(c - d)^2 + 2*c^2 + 2*d^2