有一道国外的中学数学试题: 试证:C_(2n+x)~n·C_(2n-x)~n≤(C_2n~n)~2 在讲解此题的过程中,我先引入了另一道试题,“试把17分成两个正整数部分让它们的乘积最大”,我们知道下列的事实; 1·16<2·15<…<7·10<8·9这就是说,当二数的和为定数时,它们的差(的绝对值)越小乘积就越大,事实上,由恒等 There is a foreign high school mathematics test: Testimony: C_(2n+x)~n?C_(2n-x)~n≤(C_2n~n)~2 In explaining this question, I first introduced another The test question, “Try dividing 17 into two positive integer parts to maximize their product”, we know the following facts; 1.16<2·15<...<7·10<8·9 That is, when two numbers are When the sum is a fixed number, the smaller (the absolute value) of their difference is the larger the product, in fact, by the identity