（1+1/2）x（1-1/2）x（1+1/3）x（1-1/3）x……x（1+1/99）x（1-1/
（1+1/2）x（1-1/2）x（1+1/3）x（1-1/3）x……x（1+1/99）x（1-1/后：99）
第1个回答 2018-12-20
f(x) =x(x+1)(x+2)...(x+2n)
f'(x) =(x+1)(x+2)...(x+2n)+x(x+2)...(x+2n)+x(x+1)(x+3)...(x+2n)+...
+x(x+1)(x+2)...(x+2n-1)
f'(-n)=-n(-n+1)(-n+2)....(-n+n-1)(-n+n+1)....(-n+2n)
= (-1)^n . (n!)^2
f'(x) =(x+1)(x+2)...(x+2n)+x(x+2)...(x+2n)+x(x+1)(x+3)...(x+2n)+...
+x(x+1)(x+2)...(x+2n-1)
f'(-n)=-n(-n+1)(-n+2)....(-n+n-1)(-n+n+1)....(-n+2n)
= (-1)^n . (n!)^2
第2个回答 2018-05-06
(1+1/2)x(1-1/2)x(1+1/3)x(1-1/3)x...x(1+1/99)x(1-1/99)
=3/2x1/2x4/3x2/3x5/4x3/4x...x99/98x97/98x100/99x98/99
=1/2x100/99=50/99本回答被提问者采纳
=3/2x1/2x4/3x2/3x5/4x3/4x...x99/98x97/98x100/99x98/99
=1/2x100/99=50/99本回答被提问者采纳
第3个回答 2013-12-19
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4)……(1-1/99)(1+1/99)
=1/2 ×3/2×2/3 × 4/3×3/4 × ……×98/99 ×100/99
=1/2×100/99
=50/99
=1/2 ×3/2×2/3 × 4/3×3/4 × ……×98/99 ×100/99
=1/2×100/99
=50/99
第4个回答 2020-11-26
(1+1/2)x(1-1/2)x(1+1/3)x(1-1/3)x...x(1+1/99)x(1-1/99) =3/2x1/2x4/3x2/3x5/4x3/4x...x99/98x97/98x100/99x98/99 =1/2x100/99=50/99
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