(1-1⼀2^2)(1-1⼀3^2)......(1-1⼀9^2)(1-1⼀10^2)

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2024-12-23 04:38:39
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回答1:

(1-1/2^2)(1-1/3^2)......(1-1/9^2)(1-1/10^2)
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)....(1-1/9)(1+1/9)(1-1/10)(1+1/10)
=(1/2)*(3/2)(2/3)*(4/3)*......(8/9)(10/9)(9/10)(11/10)
=(1/2)*(11/10)
=11/20
提示:运用平方差公式