3 + c 3 + d -------- + -------- 2 2 c - c*d d - c*d
(3.0 + c)/(c^2 - c*d) + (3.0 + d)/(d^2 - c*d)
/ 2 \ / 2 \
(3 + c)*\d - c*d/ + (3 + d)*\c - c*d/
---------------------------------------
/ 2 \ / 2 \
\c - c*d/*\d - c*d/ c*(3 + d)*(c - d) + d*(3 + c)*(d - c)
-------------------------------------
c*d*(c - d)*(d - c)