K的3次—K的2次=—1 求K
问题描述：
K的3次—K的2次=—1 求K
答
1/3 - (25/54 - 1/108*23^(1/2)*108^(1/2))^(1/3) - 1/(9*(25/54 - (23^(1/2)*108^(1/2))/108)^(1/3)) 1/(18*(25/54 - (23^(1/2)*108^(1/2))/108)^(1/3)) + (25/54 - (23^(1/2)*108^(1/2))/108)^(1/3)/2 - (3^(1/2)*...