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n>1,n属于正整数,证明(1+1/3)(1+1/5)(1+1/7)…(1+1/(2n—1)>√(2n+1)/2用综合法.

题目详情
n>1,n属于正整数,证明(1+1/3)(1+1/5)(1+1/7)…(1+1/(2n—1)>√(2n+1)/2 用综合法 .
▼优质解答
答案和解析
[(1+1/3)(1+1/5)(1+1/7)…(1+1/(2n-1)]²
=(1+1/3)(1+1/3)(1+1/5)(1+1/5)(1+1/7)(1+1/7).(1+1/(2n-1))*(1+1/(2n-1))
>(1+1/3)(1+1/4)(1+1/5)(1+1/6)(1+1/7)(1+1/8).(1+1/(2n-1))*(1+1/2n)
=(4/3)(5/4)(6/5)(7/6)*(8/7)*(9/8).(2n/(2n-1)) *(2n+1)/2n
=(2n+1)/3
>(2n+1)/4
所以 (1+1/3)(1+1/5)(1+1/7)…(1+1/(2n—1)>√(2n+1)/2