用配方法将二次型[img=195x23]1802ce8d3f2feb4.png[/img]化为标准形，所用的线性替换矩阵是（ ）.
A: [img=136x77]1802ce8d49ae298.png[/img]
B: [img=101x65]1802ce8d520ec6e.png[/img]
C: [img=108x71]1802ce8d5ca0ee5.png[/img]
D: [img=122x71]1802ce8d6705041.png[/img]
A: [img=136x77]1802ce8d49ae298.png[/img]
B: [img=101x65]1802ce8d520ec6e.png[/img]
C: [img=108x71]1802ce8d5ca0ee5.png[/img]
D: [img=122x71]1802ce8d6705041.png[/img]
举一反三
- 用配方法将二次型[img=195x23]1803c0a2aef5dd5.png[/img]化为标准形，所用的线性替换矩阵是（ ）. A: [img=136x77]1803c0a2bafa160.png[/img] B: [img=101x65]1803c0a2c86ba41.png[/img] C: [img=108x71]1803c0a2d312263.png[/img] D: [img=122x71]1803c0a2ddec26e.png[/img]
- 随机变量X的分布律如下表[img=210x86]17de6027b9f95df.png[/img]则D( X ) =（ ）． A: 7/8 B: 15/8 C: 71/64 D: 71/4
- 原电池（-）Pt︱Fe[img=17x22]1803dd54de61136.png[/img](1 mol·L[img=17x22]1803dd54e7299c0.png[/img]),Fe[img=17x22]1803dd54f0030fb.png[/img](1 mol·L[img=17x22]1803dd54fa39c0d.png[/img])‖Ce[img=17x22]1803dd5502f9d6b.png[/img]( mol·L[img=17x22]1803dd550b82a7d.png[/img]) ,Ce[img=17x22]1803dd55130efd2.png[/img]( mol·L[img=17x22]1803dd551af174c.png[/img]) ︱Pt(+)的电池反应是( )。 A: Ce[img=17x22]1803dd552375aee.png[/img] + Fe[img=17x22]1803dd552ca7541.png[/img] = Ce[img=17x22]1803dd5534dbdef.png[/img] + Fe[img=17x22]1803dd553dc33d1.png[/img] B: Ce[img=17x22]1803dd552375aee.png[/img] + Fe[img=17x22]1803dd553dc33d1.png[/img] = Ce[img=17x22]1803dd5534dbdef.png[/img] + Fe[img=17x22]1803dd552ca7541.png[/img] C: Ce[img=17x22]1803dd5534dbdef.png[/img] + Fe[img=17x22]1803dd553dc33d1.png[/img] = Ce[img=17x22]1803dd552375aee.png[/img] + Fe[img=17x22]1803dd552ca7541.png[/img] D: Ce[img=17x22]1803dd5534dbdef.png[/img] + Fe[img=17x22]1803dd552ca7541.png[/img] = Ce[img=17x22]1803dd552375aee.png[/img] + Fe[img=17x22]1803dd553dc33d1.png[/img]
- 设X是随机变量，且[img=139x31]1802e2aa00edf66.jpg[/img]，则D(X)=（ ）. A: 2 B: 4 C: 6 D: 8
- 已知y=f(x)是奇函数,当x≥0时,[img=62x34]17e0bf81aac3b63.png[/img],则f(-8)的值是( ) A: -8 B: -4 C: 4 D: 8