• 2022-06-16
    计算1/1×3+1/3×5+1/5×7+1/7×9+……+1/(2n-1)(2n+1)(n为正整数).
  • 1/(2n-1)(2n+1)=[1/(2n-1)-1/(2n+1)]*1/21/1×3+1/3×5+1/5×7+1/7×9+……+1/(2n-1)(2n+1)=[1-1/3+1/3-1/5+……-1/(2n+1)]*1/2=(1-1/(2n+1)]*1/2=n/(2n+1)

    内容

    • 0

      编写程序,对于输入的正整数n,输出S=1×3×5×7×…×(2n-1)值.

    • 1

      (1)5 7 9 11() () ()()(2)26 23 20 17()() 8()(3)1 2 4 7 11() () 29(4)7 3 8 3 9 3()()(5)1 1 2 3 5 8()()

    • 2

      下列数组声明语句中,不正确的是_________。 A: Dim a(9) As Single = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} B: Dim a() = {1, 2, 3, 4, 5, 6, 10} C: Dim a( ,) As Single = {{1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}} D: Dim a() As Single = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} E: Dim n As Integer=10Dim a(n) As Single

    • 3

      设`\n`阶方阵`\A`满足`\|A| = 2`,则`\|A^TA| = ,|A^{ - 1}| = ,| A^ ** | = ,| (A^ ** )^ ** | = ,|(A^ ** )^{ - 1} + A| = ,| A^{ - 1}(A^ ** + A^{ - 1})A| = `分别等于( ) A: \[4,\frac{1}{2},{2^{n - 1}},{2^{{{(n - 1)}^2}}},2{(\frac{3}{2})^n},\frac{{{3^n}}}{2}\] B: \[2,\frac{1}{2},{2^{n - 1}},{2^{{{(n + 1)}^2}}},2{(\frac{3}{2})^n},\frac{{{3^n}}}{2}\] C: \[4,\frac{1}{2},{2^{n + 1}},{2^{{{(n - 1)}^2}}},2{(\frac{3}{2})^{n - 1}},\frac{{{3^n}}}{2}\] D: \[2,\frac{1}{2},{2^{n - 1}},{2^{{{(n - 1)}^2}}},2{(\frac{3}{2})^{n - 1}},\frac{{{3^n}}}{2}\]

    • 4

      有六组量子数: (1) n=3,l=1,m=-1;(2) n=3,l=0,m=0;(3) n=2,l=2,m=-1;(4) n=2,l=1,m=0;(5) n=2,l=0,m=-1;(6) n=2,l=3,m=2 其中正确的是( )。 A: (1)(3)(5) B: (2)(4)(6) C: (1)(2)(4) D: (1)(2)(3)