-18*z ----------------------- 3 2 -729 + z - 81*z + 9*z
-18*z/(-729 + z^3 - 81*z + 9*z^2)
1/(2*(9 + z)) - 9/(9 + z)^2 - 1/(2*(-9 + z))
1 9 1 --------- - -------- - ---------- 2*(9 + z) 2 2*(-9 + z) (9 + z)
/ 2\ 2 z*\-81 + z / - z*(9 + z) ------------------------- / 2\ 2 \-81 + z /*(9 + z)
(z*(-81 + z^2) - z*(9 + z)^2)/((-81 + z^2)*(9 + z)^2)
-18*z ----------------------- 3 2 -729 + z - 81*z + 9*z
-18*z/(-729 + z^3 - 81*z + 9*z^2)
/ 2 2\ z*\-81 + z - (9 + z) / ----------------------- / 2\ 2 \-81 + z /*(9 + z)
z*(-81 + z^2 - (9 + z)^2)/((-81 + z^2)*(9 + z)^2)
-z/(-81.0 + z^2) + 0.0123456790123457*z/(1 + 0.111111111111111*z)^2
-z/(-81.0 + z^2) + 0.0123456790123457*z/(1 + 0.111111111111111*z)^2