Page 159 - Fixtures
P. 159

@ @pbjïØ Üa@                                                 @QTT

                               [AIME 1986] ( )

            1 − x + x2 − x 3 + + x16 − x17                             )
a0 + a1y + a2y2 + + a16y16 + a17y17
                                                                       )
                    a2 ai ,y = x + 1                                   )
                                        [AIME 1991] (                  )

                               (1 + 0.2)1000

(1 + 0.2)1000 = C (1000, 0)(0.2)0 + C(1000, 0.2)1

                 +C (1000, 2)(0.2)2 + + C(1000,1000)(0.2)1000

                = A0 + A1 + A2 + + A1000

  k .k = 0,1, ,1000 , Ak = C(1000,k)(0.2)k

P0(x) = x 3 + 313x2 − 77x − 8                   Ak

                      .n ≥ 1        [AIME 1993] (

                               Pn (x) = Pn−1(x − n)

          P20(x )                   x

       n                       [AIME 1996] (

.         1996 (xy − 3x − 7y − 21)n

                        [AIME 2000 II] (

    1+1+1+1+1
2 !!× 17 ! 3 !!× 16 ! 4 !!× 15! 6 !!× 13! 7 !!× 12 !

                                    +1 + 1 = n
                                       8 !!× 11! 9 !!× 10 ! 1!!× 18 !

                                          n

                                         100
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