• 2022-06-15
    求一个正交变换把二次曲面的方程 [tex=7.429x1.286]6bEpj2XYV2Y9+0UUtctIFMzyHxa86SJYraduW99laS4=[/tex][tex=9.214x1.286]yRqLYw/JCULXechdAGayMn8EOMoJfqv0I594akrQ+5g=[/tex]化成标准方程.
  • 解: 二次型的矩阵为 [tex=10.714x3.929]r+tiAx6ClSaeP7cZbqpjmcqapyWb2qPH4CInt8ZQy4CvWCYGzIy2PojlwIRxWV6RqSTiTypd2TWcxv02jTvaYi5CV6MZF8EdzvRgKzEZthQ8qe2htQvwNmN5BxPcuynR[/tex].[br][/br]由 [tex=4.857x1.286]vAGON7+JxTsi8RkBcCBNjAjmBCyJETqaqp6eS+1VeZw=[/tex][tex=20.0x3.929]mqOKs44jrJgbK/+3e5yEgXi2AVLTnKY7e/SQ+Gli609utmginj+9y6Huat3qSZjZpunsDygCsXWUxi4pEI9BymN6dMe2Zh0U8d2ZH+hcmCFWi+J8cqZbR/C9jUh81ifHfKt6MnfQaL0oXHwXYF+9r8oC4dWoYm5N6oko8wHdb091dxBvLYJYL8kclnlii3AC[/tex], 得 [tex=0.786x1.286]pi/GsQ3apuRt43V3XQq/tA==[/tex] 的特征值为 [tex=2.786x1.286]1WFIN2/QJ+MFq6lLX6daBvHU6YGkl48p8pxzHBv2bME=[/tex], [tex=3.286x1.286]myTeU4CP3WN7KhWItESncuGYRasHuqYgdqjK1Ff/CwA=[/tex], [tex=2.786x1.286]kEoDtco6T9rHlJBVx2M+DfsvvxEahCGwEXxKqPsbmgg=[/tex],对于 [tex=2.786x1.286]1WFIN2/QJ+MFq6lLX6daBvHU6YGkl48p8pxzHBv2bME=[/tex], 解方程[tex=6.286x1.286]6xpilGKIjvXNptemdwmBsLu8HEnHVLepnMR7VdgBbLc=[/tex], 得特征向量 [tex=4.429x1.286]LrGIXVq+Cm0HHIbze7PVVLgWTQBriRiQatTQSulsmEs=[/tex], 单位化得 [tex=11.214x2.357]voKWfhIrma2NEFOQKiok+XTd/mSDKBUWcH8tnmWKuqgEvZaUM0M7+xHDEiZ6CCniqEG7QUyfmKrD1e+sds5+XkSrMXJg0hLXTJGBX5xNA3ljX0DXQ6gvEG33JBRktuj1[/tex].对于 [tex=3.286x1.286]myTeU4CP3WN7KhWItESncuGYRasHuqYgdqjK1Ff/CwA=[/tex], 解方程 [tex=6.786x1.286]6rZvY7hHkVVkmbIz1zMOoZXYXLzWhQjONHlw/AswSTE=[/tex], 得特征向量[tex=4.429x1.286]+D14KapXShJl4UFJrjVn1hqVdSHX1BV2BqQB077ZvOg=[/tex] , 单位化得 [tex=7.286x2.357]vp7vTfBhfpPBu4RnIASO01tFxunV1NZPTVNwhF2L/gqZrmS2L9wCYGuDxoXRtNXg6BkUTESOyOg7EOxrDQ24lA==[/tex].对于 [tex=2.786x1.286]kEoDtco6T9rHlJBVx2M+DfsvvxEahCGwEXxKqPsbmgg=[/tex], 解方程 [tex=3.071x1.286]qUp7hnqkAcAqBP1QokEYww==[/tex], 得特征向量 [tex=3.714x1.286]5nKDCbL7peSfx72xqljEJ1KEEKLFQOWIqDimPLefQhc=[/tex], 单位化得[tex=7.929x2.357]ceED2XdvxXt1MPYLhqE/HSEDeFqUR/m9rSQ6ZZn16DPFpJZZBgEsdCghxpJAp1Pmj0aTHgYF7W2hcK7PZffhsz47S6ASbzvCjaoJ7wmnkeg=[/tex]于是有正交矩阵 [tex=6.429x1.286]Zh6eOjHYxWysFAM95QqAPx+QxZMl3+gE7b+jmOFbzU17KRYXrPO8sKxAYY++Ve0Q[/tex],使 [tex=10.0x1.5]0PzwzrWglTqF3GVYSX6F7IPQozaSYgvAhgGM7Cb0O7qBgtVjBqYp1CpAPKunJYLt[/tex], 从而有正交变换[tex=19.0x8.357]rwMhqGKFQ+j3l2qMx/grPkZ5gU6RsEFbhiKGlzmDyRhSftRhfdoYZtJ5K4ui1VPtGCOnKTGF83raIXDAVylDj2V0Qanltk2Bt8kXGYeGdzNuU76qYzpOjOkgegmxKg327z/zfm4tocKXQd25zCPDgGIeEnXuslxF4jb+qor6NLxH6fcJyp1L+mrfg05Wu5KwdWpuU6HbbQ4e9a2QqpFJAmeHmS0u4Pg4aarsDpXZSBNhYbKmFRcM7/wCygkmnzI0mfOXIK15eHAfgHkioOY7DByx7PNHC2VFoZQyUi51kw44gPWBpeoU4IniDXzPnHh8Civbm3Fuu3XOoCMughusDL22dp963IVfSs0DpGA2o/Vv6jRJAy2arLzpaqzvbFzWn2QgFra39kNL6he0QFgnwYXFFJptIx6We7IPj6rt9bM=[/tex],使原二次方程变为标准方程 [tex=6.357x1.286]ATgABYQj+l+MKTrKIiVsmemO4Dd+Pootf2HJ31r/MBU=[/tex].
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    内容

    • 0

      已知二次曲面方程[tex=13.5x1.429]1CP2KHAC505MQsbmvGIq9W70E0MVYb2ohUzk2/DF5j86Ff3AcUxGpzH8DLbI1K0B[/tex]可以经过正交变换[tex=4.143x3.357]075gCzZzsMRb6HYXYk9X96r0kWKSapX3uFTiObPnpwgbpgDJjGmwyFhEy1SS/CpGphg7+3kGHwN+gYMS9l8Tcg==[/tex][tex=4.071x3.929]2ezvtcDQhuL54VYrfhVgJAzy35IuQjXfObwR7Xm2C4U3sbudBVMLdkVsbOGPk+9Q8H/fen+DdC+qCs+DcVZg3Q==[/tex]化为椭圆柱面方程[tex=4.857x1.429]2XbAS0+x19tEebyG4hC3c+Psiqxxu01s26eN8c5iY3s=[/tex],求[tex=1.429x1.214]HCTRLtzxkeBZo1HKwKR3/g==[/tex]的值和正交矩阵[tex=0.786x1.0]sq7G4PRDD8RfcSH18ue4vg==[/tex].

    • 1

      已知二次曲面方程[tex=13.5x1.429]oeHjg68ojxgLI0YA8cW4laeC5UljoC0+SqxJsXiWhHfG0A7sYiNL9m1Jgc0OY48t[/tex] 可以经过正交变换 [tex=8.786x1.5]h7NtLIQFV66+jzial+TxxEkxEECbymN8gWsaGX5veCbWBcn3L8AI8eYB8NH5e7hr6qnc0yz9DSWFrR2wnfos/w==[/tex]化为椭圆柱面方程 [tex=4.429x1.429]yH8Ky55g/pzu2D+6YlGilJy1rVFDHowTNjH8BEg7jkM=[/tex] 。求 [tex=1.286x1.214]rkgrF+YaaESwSQDjR6KfWg==[/tex]的值和正交矩阵[tex=0.857x1.0]3dL6VJHKHZnugLK8MQRDDg==[/tex]。

    • 2

      利用坐标变换使方程[tex=3.5x1.429]udtIIahB5iVp7t7QwgrZ2g==[/tex] 中减少一个一次项,化成标准方程,指出是何种曲面.

    • 3

      已知二次型[tex=8.429x1.5]laEzR1IUAbB3F6co2ymLhc4Tm5xpwYK3+nsgsnQcCAsJTHAukGuXRuuRwDrPbo64[/tex]通 过正交变换化成[tex=4.929x1.5]1IFe5Z4Y60Mc26mdSv1jgS/OYq9LsnQcTJ3kfzjfDzQ=[/tex],方程组[tex=2.929x1.0]AJjUpBS0VJylgJggEDF/WQ==[/tex]有解[tex=5.071x1.5]+x/iCm2G7JZgrN3iJ+KwGwBbV0nZFFu3MEvsFdDEn2s=[/tex],求所作的正交变换及二次型的矩阵[tex=0.786x1.0]kEam2pLJe4uAYVdcny2W5g==[/tex] .  

    • 4

      设 [tex=0.857x1.286]RFrkvDyvKeTvv0Y+OA8C+g==[/tex] 为3阶实对称矩阵,如果二次曲面方程 [tex=7.929x4.786]NitsHaULuaExHn+3RErpEniiw1KBQGC1KMx1bcLK0c1PiYX1CV0nyn+YtlajwjVI8K8gCp2zC9i/l2PK8LEtbQ==[/tex] 在正交变换下的标准方程的图形如图所示,[img=194x149]1568ccde22847d0.png[/img]则 [tex=0.857x1.286]RFrkvDyvKeTvv0Y+OA8C+g==[/tex] 的正特征值的个数为(  )。 A: 0 B: 1 C: 2 D: 3