计算定积分[tex=7.214x2.786]/2GFao47NM0IuCyxoLtKRqIBjReFjuRD7doocOFm7R/tNF9Q2Irzir+cR2bbFiat[/tex].

用定积分的换元法计算积分：[tex=7.214x2.786]s1b1uUpHFXk78mxB3L2JgBTTFBZj7KKtzv85WyfuoI1zTkRgBGnlU2iXQfmL5uAslW5W54FfPzKITX/yvKnwVg==[/tex]

 用定积分的换元法计算下列积分：[tex=7.214x2.786]Pdz2GHkIEDDQHxTDEFSF/yQbSJv+BMravk4mElJS4J9KbMUf/KJiLPN68nhDenkmhKAqemji4ST6AGfC1nFdpw==[/tex]

在下列曲线上求曲率为极值的点 (曲线顶点）：[tex=7.214x2.786]7EJHVCtO2IWq3KpdB+jQsisZgd4rCWyn+y/rlXBvaOeMd65AHEGxnBxA505w92Vi4CKgDPpUzALO3NvJJSLjeFdbuxBbTrYbrf+pVwrOfKU=[/tex]

定积分 [tex=7.214x2.786]WdYFOXfG5nnGW/WgiEfXS5TgSbC/oF1MRp/6H8KOnmKg/kgj7C6k4LHGjG3GAitV/7dsLPk/KT/eRmxWcJluPg==[/tex]. A: 2 B: -1 C: 1 D: 0

设分块实对称矩阵 [tex=7.214x2.786]Kz/o07mNehCgwSeK1E3mwPLwwc5QkJSWRsp6GiZ0lXp1tzGiTyEqcWXJGjw0cyxwldE6HtmGI9kWEuoLfJ0lqVxmqug2hVlDusJT5blD4gw=[/tex], 其中 [tex=2.0x1.214]+hJWInEjZxEp+ROBrtaQZg==[/tex] 都可逆, 求证: [tex=21.143x3.5]Ck4j1YFlvVH5wCAykOEMi9cqHKFnbc5zfcQJ8wxjo94Y0oiIakz5hF566bfgBVfbMbfMf0WQNNg6z5IqRPYBS/+Cwwhr0fun6+2vtSGMG5Ggh8nuzSig3x9Eo9q81MOl1oTQlDb8A1Bng655nJGbfWPIdcZaKZDk8pICzAJ3HQN9b+bIYTXR3v7vgDITekShm3qXmT/pUcZqfXV0y4ICpCgWTp89ZLRjPH4sZn71Uf+ieZzGgAoJkFSYdElA1uQzC2QHSdnrgHivXtknwmUWhJJUfAzcAzmgyr8Q/cl7WF2b2Bhc6YLmNB5nNRHJT3tp[/tex]

已知二次曲线通过原点并且以下列两对直线[tex=7.214x2.786]fnpmC2J6JmQBLyo5NmGAz1eyH3MQOWyj2CqV/dyv/SSM6N35j9P43OxAtJCsRmCeyFGhEuMsZDM9fSGZWzfn6WNcr1FGxwsTOMmw7vBM//8=[/tex]与[tex=6.714x2.786]fnpmC2J6JmQBLyo5NmGAz9E4gQvvcnM5VKQET9vqDMTfeXi5Y6DP6tE3XqbiBiJs00ORXnmg9A90lvXFCeiSfA==[/tex]求它的两对共轭直径，求这二次曲线的方程.

下列反常积分中收敛的是 未知类型：{'options': ['[tex=5.786x2.714]H2GMnQeFo+SnTMgvzs7W65KrPz5tfCG0J10Joal8D4VFJsUXoWWgjq5lnMYlvH74[/tex]', '[tex=6.5x2.714]H2GMnQeFo+SnTMgvzs7W65hx7dxz/9RLDj5nht8roqhg/Tmq4mbUusOHyalC3Pv4[/tex]', '[tex=7.5x2.786]H2GMnQeFo+SnTMgvzs7W65hx7dxz/9RLDj5nht8roqhAQqO/zVUTNWcmRc6sN11E+8VIqVThRDr1og+FadheMA==[/tex]', '[tex=7.214x2.786]H2GMnQeFo+SnTMgvzs7W65hx7dxz/9RLDj5nht8roqizoMuRsujL97bAHzuqTRcT3PuNlvZMziL1NaRDbRuX7Q==[/tex]'], 'type': 102}

和矩阵 [tex=7.214x2.786]rGs53XpO8zahy2DDDvYP4fLUSdNDEiWSvF+gtoDb3cmSVIO194nwkdEJsZ+8tb1PQymYsLzVcba8n6BaJQPFmw==[/tex] 正交相似的矩阵是 未知类型：{'options': ['[tex=4.5x2.786]jcCMHflCR8OS9TosV6N5vMkHTRHzWo810v8QRVT0g3iIrbBisQQHPhUbdUi+Iuw9o7zBD6vTVYB9q+/S6r/0dg==[/tex]', '[tex=5.286x2.786]jcCMHflCR8OS9TosV6N5vJBeRqwuxAsinVmkBpgk+kZzE2j842MKJH+KEcdqvm/36yx1w3aopcuwUhTVZ+4clQ==[/tex]', '[tex=5.286x2.786]jcCMHflCR8OS9TosV6N5vNL2MiM3fXibWm3ix8LvZzpvd31avnNbu2U81fYkVNp7dAuJS3rtG9QEEGWMTp3bZA==[/tex]', '[tex=5.143x2.786]jcCMHflCR8OS9TosV6N5vJPKTza1UrQuRfSxrADuqhfX5eL4BXj4zEMisRcoyyogakn0dAMkPAkUkGLyWJYsKQ==[/tex]'], 'type': 102}

下列变量组（）是一个闭回路。 A: {x，x，x，x，x，x} B: {x，x，x，x，x} C: {x，x，x，x，x，x} D: {x，x，x，x，x，x}