计算二阶行列式:[tex=4.429x2.786]TIwZYBkNsy31H1RNd/OloJ+bwHcoAdtdjclWdVrEteU3NXnL+Elqs3tYku6BTFfZnmUP6LlzyorrwV49WzrkQM/2vYcZhDt+p5mkOZ6JHOA=[/tex]
举一反三
- 设随机变量X的分布律为P{X=-1}=1/6, P{X=0}=1/3, P{X=1/2}=1/6, P{X=1}=1/12, P{X=2}=1/4, 则E(X²)= ( ). A: 1/3 B: 2/3 C: 31/24 D: 4/3
- 求函数$y = {{1 + \root 3 \of {{x^2}} - \sqrt {2x} } \over {\sqrt x }}$的导数$y' = $( ) A: $ {1 \over 2}{x^{ - {3 \over 2}}} + {1 \over 6}{x^{ - {5 \over 6}}}$ B: $ - {1 \over 2}{x^{ - {3 \over 2}}} + {1 \over 6}{x^{ - {5 \over 6}}}$ C: ${1 \over 2}{x^{ - {3 \over 2}}} - {1 \over 6}{x^{ - {5 \over 6}}}$ D: ${1 \over 3}{x^{ - {3 \over 2}}} - {1 \over 6}{x^{ - {5 \over 6}}}$
- 39号元素钇的核外电子排布式是下列排布中的（ ） A: 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 3 d 10 4 s 2 4 p 6 4 d 1 5 s 2 B: 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 3 d 10 4 s 2 4 p 6 5 s 2 5 p 1 C: 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 3 d 10 4 s 2 4 p 6 4 d 2 5 s 1 D: 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 3 d 10 4 s 2 4 p 6 5 s 2 5 p 1
- 计算下列 2 阶行列式:[tex=4.5x2.786]TIwZYBkNsy31H1RNd/OloKwLzaoT22WbZlzLNOIWMHxpktBhyHDWbPEWjImbaTs6Vz86AR47KcDl/MHWrqQsbg==[/tex].
- 计算下列 2 阶行列式:[tex=3.714x2.786]TIwZYBkNsy31H1RNd/OloH3/CgabWSLl1FutsljM3RDBXQUZMxHAaLdEv449kfWClTZ794s65JN+iPCdbIyREQ==[/tex].