二次型[img=187x51]1803df7d3823058.png[/img],其中[img=103x28]1803df7d414f1aa.png[/img]对应的矩阵是
A: [img=60x51]1803df7d4913249.png[/img]
B: [img=60x51]1803df7d50b5b22.png[/img]
C: [img=88x51]1803df7d57f1e66.png[/img]
D: [img=88x51]1803df7d61177d9.png[/img]
A: [img=60x51]1803df7d4913249.png[/img]
B: [img=60x51]1803df7d50b5b22.png[/img]
C: [img=88x51]1803df7d57f1e66.png[/img]
D: [img=88x51]1803df7d61177d9.png[/img]
举一反三
- 要求方程[img=69x27]1802e4da216c9dd.png[/img]的解，应使用命令 A: dsolve('Df=x^2') B: dsolve('Df==x^2') C: dsolve('Df=x^2',x) D: dsolve('Df==x^2',x)
- 二次型[img=187x51]18031764efef478.png[/img],其中[img=103x28]18031764f89ee7d.png[/img]对应的矩阵是 A: [img=60x51]1803176501507ee.png[/img] B: [img=60x51]180317650a48109.png[/img] C: [img=88x51]18031765123e993.png[/img] D: [img=88x51]180317651b7cea2.png[/img]
- 设X，Y为两个随机变量，且[img=179x25]1803395d555effc.png[/img] , [img=226x25]1803395d61f1a43.png[/img] ,则[img=143x25]1803395d6f00057.png[/img]= ( )． A: 1/7 B: 3/7 C: 4/7 D: 5/7
- 矩阵 是二次型[img=122x27]1803df7d401d270.png[/img]的矩阵 A: [img=88x51]1803df7d47b58fa.png[/img] B: [img=60x51]1803df7d4f9e073.png[/img] C: [img=60x51]1803df7d57c4d4e.png[/img] D: [img=60x51]1803df7d60782ce.png[/img]
- 矩阵 是二次型[img=122x27]1803176519395aa.png[/img]的矩阵 A: [img=88x51]1803176521b89a6.png[/img] B: [img=60x51]18031765295144f.png[/img] C: [img=60x51]18031765324c8be.png[/img] D: [img=60x51]180317653b4377c.png[/img]