2 / 4 8\ x *\-100 + 81*x *y /
/ ____\ / ____\ / ____\ / ____\ | \/ 10 | | \/ 10 | | I*\/ 10 | | I*\/ 10 | x*|x + ------|*|x - ------|*|x + --------|*|x - --------| | 2 | | 2 | | 2 | | 2 | \ 3*y / \ 3*y / \ 3*y / \ 3*y /
2 / 2 4\ / 2 4\ x *\-10 + 9*x *y /*\10 + 9*x *y /