A是n阶实方阵，则A是正交矩阵的充要条件时（ ）
未知类型：{'options': ['[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_160765c0-82ae-41e7-92cc-7f9f38df73cf.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_f91bd7e2-e47b-421c-a1f4-c37277340526.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_0156ee63-63f2-4377-90e7-ee87b08fc01b.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_bb7bc755-5c94-491e-9545-af103b5d2bf3.png"]'], 'type': 102}
未知类型：{'options': ['[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_160765c0-82ae-41e7-92cc-7f9f38df73cf.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_f91bd7e2-e47b-421c-a1f4-c37277340526.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_0156ee63-63f2-4377-90e7-ee87b08fc01b.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_bb7bc755-5c94-491e-9545-af103b5d2bf3.png"]'], 'type': 102}
举一反三
- 下列矩阵，哪一个是正交矩阵（ ） 未知类型：{'options': ['[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_e3bcbe32-bf4f-4dd7-87eb-435166d4a694.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_2dd5a805-5f17-4578-950f-b0e99cb4ace5.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_fb404ce8-29fb-4a21-9f66-2e1cc1e8e6b2.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_6238ef9e-3ec5-4c01-8429-4fbbb82bc5ff.png"]'], 'type': 102}
- 设三阶方阵A的秩是2，则与A等价的矩阵为（ ） 未知类型：{'options': ['[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_2a68ab7b-9b7e-4607-abde-e255189c845c.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_208fb5a8-85c0-4a53-8cf2-673752bf5034.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_08c0964d-f78b-44eb-ac06-5c18ec1142e0.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_3d5b7bfd-bef2-4920-8749-90e0f59a4770.png"]'], 'type': 102}
- 设A，B为任意两个n阶方阵，则下列一定成立的是 （ ） 未知类型：{'options': ['[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_33399133-78a2-46d1-b0e6-585d3e1a61fa.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_d308b840-8167-4c60-98c2-50ad54a58d80.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_0836c6f0-9141-4013-8ffa-bd3be454df0a.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_46c561a2-1836-4982-9c80-e1bbc2dc9af1.png"]'], 'type': 102}
- 以下对相关系数与回归系数的描述正确的是 未知类型：{'options': ['[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_a239429a-7fee-4b87-8988-34ecbff62f78.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_8e840276-5eb5-496e-99e5-dbf0fc08a23b.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_44c8e13f-08e0-425a-b275-0409b8954e16.png"]', '[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_b013f5a5-447f-46ad-89ec-f4a2c5927468.png"]'], 'type': 102}
- 设[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_067016aa-77f2-4aff-bd36-e3fa5f1bd893.png"],[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_358ab06c-7f19-4ae6-ba82-424c72bd4d18.png"],则[img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_2b561af0-b65d-4e5e-936b-72b15b4f0f56.png"][img src="http://edu-image.nosdn.127.net/_PhotoUploadUtils_92284d1b-6fe3-4dc1-a732-618796cd01a4.png"] A: 6 B: 10 C: 8 D: 4