用数学归纳法证明:1+1\/2^2+1\/3^2+...+1\/n^2<(2n-1)\/n
证明:1+1\/2^2+1\/3^2+...+1\/n^2<(2n-1)\/n (n>=2,n属于N*)1)1+1\/2^2=5\/4 < 3\/2 2) 设:1+1\/2^2+1\/3^2+...+1\/k^2<(2k-1)\/k,1+1\/2^2+1\/3^2+...+1\/k^2+1\/(k+1)^2<(2k-1)\/k+1\/(k+1)^2 =(2k^3+4k^2+2k-k^2-2k-1+k)\/k(k+1...
1+1\/(2^2)+1\/(3^2)+1\/(4^2)+…+1\/(n^2)<1-1\/n 用数学归纳法证明
1.当n=2时,左边=1\/2^2=1\/4,右边=1-1\/2=1\/2,左边<右边,成立 2.假设当n=k时,1\/2^2+1\/3^2+...+1\/k^2<1-1\/k 所以:当n=k+1时,左边=1\/2^2+1\/3^2+...+1\/k^2+1\/(k+1)^2 <1-1\/k+1\/(k+1)^2 =[1-1\/(k+1)]+[1\/(k+1)-1\/k+1\/(k+1)^2]...
用数学归纳法证明1+1\/2²+1\/3²+...+1\/n²<2-1\/n n≥2
证明:1.当n=2时,1+1\/4<2-1\/2,命题成立;2.假设n=k时,1+1\/2^2+1\/3^2+...+1\/k^2<2-1\/k,(k属于自然数集且n大于等于2),那么n=k+1时,1+1\/2^2+1\/3^2+...+1\/k^2+1\/(k+1)^2<2-1\/k+1\/(k+1)^2=2-(k^2+k+1)\/k(k+1)^2<2-(k^2+k)\/k(k+1...
用数学归纳法证明:1+1\/22+1\/32+……+1\/n2 ≥3n\/2n+1
用数学归纳法证明:1 + 1\/2² + 1\/3² + …… + 1\/n² ≥ 3n \/ (2n+1)(1) 当 n=1时 左端 = 1 右端 = 3\/3 = 1, 因为 1 ≮1 ,所以≥成立;(2) 假设 当n = k时等式成立,即 1 + 1\/2² + 1\/3² + …… + 1\/n² ...
数学归纳法证明: 1+1\/2∧½+1\/3∧½+…+1\/n∧½ > 2(n∧...
既然是数学归纳法..应该很简单了..当n=1时,3n\/(2n+1)=1,满足;若n=k时成立(k≥1),则1+1\/2^2+1\/3^2+…+1\/k^2≥3k\/(2k+1);则1+1\/2^2+…+1\/k^2+1\/(k+1)^2≥3k\/(2k+1)+1\/(k+1)^2;3k\/(2k+1)+1\/(k+1)^2-(3k+3)\/(2k+3)=(k^2+2k)\/((k+1)^2*(...
数学归纳法证明1+1\/2+1\/3+……+1\/2^n>n+1\/2
令 f(n)=1+1\/2+1\/3+……+1\/2^n g(n)=(n+1)\/2 原题成为f(n)>g(n)当n=1时, f(n)=1+1\/2=3\/2 > g(n) = (1+1)\/2, 原等式成立 下面证明对于任意n, 当f(n-1)>g(n-1)成立时, 恒有f(n)>g(n)成立 只需证明f(n)-f(n-1) > g(n)-g(n-1)即可 而g(...
用数学归纳法证明1+1\/2^2+1\/3^2+```+1\/n^2<2-1\/n
证明 n=2时,左边=1+1\/2^2=1+1\/4 右边=2-1\/2=1+1\/2 左边<右边 假设n=k时左边<右边成立 即1+1\/2^2+1\/3^2+...+1\/k^2<2-1\/k n=k+1时 左边 =1+1\/2^2+1\/3^2+...+1\/k^2+1\/(k+1)^2 <2-1\/k+1\/(k+1)^2 =2-(k^2+k+1)\/[k(k+1)^2]∵k^2+k+...
选择题:用数学归纳法证明“1+1\/2+1\/3+…+1\/2^n-1<n(n∈N*,n>1)”时...
n=k时,左边= 1+1\/2+1\/3+…+1\/(2^k -1)n=k+1时,左边= 1+1\/2+1\/3+…+1\/[2^(k+1) -1]=1+1\/2+1\/3+…+1\/(2^k -1) +1\/2^k +1\/(2^k +1) +……+1\/[2^(k+1) -1]增加的项是 1\/2^k +1\/(2^k +1) +……+1\/[2^(k+1) -1]从2^k到 2^...
用数学归纳法证明1^2\/1·3+2^2\/3·5+...+n^2\/(2n-1)(2n+1)=n(n+1...
(1) n = 1 时 左边 = 1\/3, 右边 = 2\/6 = 1\/3, 右边 = 左边 (2)设 n = k (>1)时, 左边 = k(k+1) \/ [2(2k+1)]当 n = k+1 时, 左边 = k(k+1) \/ [2(2k+1)] + (k+1)^2 \/ (2k+1)(2k+3)= (k+1)*(2k+1)*(k+2) \/ 2(2k+1)(2k+3)...
数学归纳法证明1+1\/2+1\/3+……+1\/2^n>n+1\/2
n=2时 左边=1+1\/2+1\/3+1\/4=2+1\/12<2+1\/2 题目应该改成≤,下面用数学归纳法证明 1)当n=1时,显然成立;2)假设当n=k (k≥1)时不等式成立,即 1+1\/2+1\/3+...+1\/(2^k)≤k+1\/2 于是 当n=k+1时,1+1\/2+1\/3+...+1\/(2^k)+1\/((2^k)+1)+1\/((2^k...