在298.15K时,ΔbHϴm(F-F)=158kJ·mol–1,ΔbHϴm(N≡N)=946kJ·mol–1,ΔbHϴm(F-N)=272kJ·mol–1,反应3F2(g)+N2(g) = 2NF3(g) 的ΔrHϴm等于
在298.15K时,ΔbHϴm(F-F)=158kJ·mol–1,ΔbHϴm(N≡N)=946kJ·mol–1,ΔbHϴm(F-N)=272kJ·mol–1,反应3F2(g)+N2(g) = 2NF3(g) 的ΔrHϴm等于
图示矩形截面对x、y,两形心轴的惯性矩分别为()。 A: I=(1/12)bh,Iy=(1/12)hb B: I=(1/12)bh,Iy=(1/12)hb C: I=(1/12)hb,Iy=(1/12)bh D: I=(1/12)hb,Iy=(1/12)bh
图示矩形截面对x、y,两形心轴的惯性矩分别为()。 A: I=(1/12)bh,Iy=(1/12)hb B: I=(1/12)bh,Iy=(1/12)hb C: I=(1/12)hb,Iy=(1/12)bh D: I=(1/12)hb,Iy=(1/12)bh
若BX=4321H, 则运行程序:OR BL, 0F6H BL=ROR BL, 1 BL=INC BL BL=SUB BH, 1 BH=BX=
若BX=4321H, 则运行程序:OR BL, 0F6H BL=ROR BL, 1 BL=INC BL BL=SUB BH, 1 BH=BX=
已知()y()=()ln()x(),则()y()(()n())()=()。A.()(()−()1())()n()n()!()x()−()n()"()role="presentation">()(()−()1())()n()n()!()x()−()n();()B.()(()−()1())()n()(()n()−()1())()!()x()−()2()n()"()role="presentation">()(()−()1())()n()(()n()−()1())()!()x()−()2()n();()C.()(()−()1())()n()−()1()(()n()−()1())()!()x()n()"()role="presentation">()(()−()1())()n()−()1()(()n()−()1())()!()x()-n();()D.()(()−()1())()n()−()1()n()!()x()−()n()+()1()"()role="presentation">()(()−()1())()n()−()1()n()!()x()−()n()+()1().
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已知数列{ a n }, a 1 =1, a n - a n - 1 =1 ( n ≥2).则 a 5 =( )
已知数列{ a n }, a 1 =1, a n - a n - 1 =1 ( n ≥2).则 a 5 =( )
求n!问题,表示算法的复杂性的递归函数下述正确的是? A: T(n)=O(1),当n=1 T(n)=T(n-1)+O(1),当n>1 B: T(n)=O(1),当n=1 T(n)=nT(n-1)+O(1),当n>1 C: T(n)=O(1),当n=1 T(n)=2T(n/2)+O(1),当n>1 D: T(n)=O(1),当n=1 T(n)=T(n/2)+O(n),当n>1
求n!问题,表示算法的复杂性的递归函数下述正确的是? A: T(n)=O(1),当n=1 T(n)=T(n-1)+O(1),当n>1 B: T(n)=O(1),当n=1 T(n)=nT(n-1)+O(1),当n>1 C: T(n)=O(1),当n=1 T(n)=2T(n/2)+O(1),当n>1 D: T(n)=O(1),当n=1 T(n)=T(n/2)+O(n),当n>1
【单选题】已知数列{a n }中,a 1 =1,当n≥2时,a n =2a n - 1 +1,依次计算a 2 ,a 3 ,a 4 后,猜想a n 的一个表达式是()(5.0分) A. n 2 ﹣1 B. (n﹣1) 2 +1 C. 2 n ﹣1 D. 2 n ﹣ 1 +1
【单选题】已知数列{a n }中,a 1 =1,当n≥2时,a n =2a n - 1 +1,依次计算a 2 ,a 3 ,a 4 后,猜想a n 的一个表达式是()(5.0分) A. n 2 ﹣1 B. (n﹣1) 2 +1 C. 2 n ﹣1 D. 2 n ﹣ 1 +1
排列\( n(n - 1)(n - 2) \cdots 3 \cdot 2 \cdot 1 \)的逆序数是( ) A: \( {1 \over 2}n(n - 1) \) B: \( n(n - 1) \) C: \( n \) D: \( {n^2}(n - 1) \)
排列\( n(n - 1)(n - 2) \cdots 3 \cdot 2 \cdot 1 \)的逆序数是( ) A: \( {1 \over 2}n(n - 1) \) B: \( n(n - 1) \) C: \( n \) D: \( {n^2}(n - 1) \)
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: \[2,\frac{1}{2},{2^{n - 1}},{2^{{{(n - 1)}^2}}},2{(\frac{3}{2})^{n - 1}},\frac{{{3^n}}}{2}\]
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: \[2,\frac{1}{2},{2^{n - 1}},{2^{{{(n - 1)}^2}}},2{(\frac{3}{2})^{n - 1}},\frac{{{3^n}}}{2}\]
若1的n次方+(-1)的n次方/6=(-1)的n次方+(-1)的n次方+1/6,则n为?
若1的n次方+(-1)的n次方/6=(-1)的n次方+(-1)的n次方+1/6,则n为?