f ( x, y ) = cos ( xy ) | p ( x, y ) = 1 - x 2y 2 / 2 |
p ( x, y ) = 1 - x 2y 2 / 2 + x 4y 4 / 24 |
p ( x, y ) =
1 - x 2y 2 / 2 + x 4y 4 / 24 - - x 6y 6 / 720 |
f ( x, y ) = cos ( xy ) |
p ( x, y ) =
1 - x 2y 2 / 2 + x 4y 4 / 24 - - x 6y 6 / 720 + x 8y 8 / 40320 |