, . . .: ax3 + bx2 + cx + d = 0,

¹ 0. , = - b/3a, . . () : y3 + py + q = 0,

p =-b2/3a2 + c/a, q =2b/27a3 - bc/3a2 + d/a,

: .
. . - , q2/4+p3/27, . q2/4 + p3/27>0, . . : , - ; q2/4+p3/27 =0, , ; q2/4+p3/27 <0, . q2/4+p3/27 . . D = -4p3- 27q2.
.: . ., , 9 ., ., 1968; , . . . ( .), . 2, .- ., 1951.

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