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已知曲线C:xy-4mx2my20m-20=0(1)求证:不论?

2018-03-08 02:18:10内***
已知曲线C:xy-4mx2my20m-20=0。(1)求证:不论m取何实数,曲线C恒过一定点;(2)求证::x^2 y^2-4mx 2my 20m-20=0 (?

最佳回答

  • x^2 y^2-4mx 2my 20m-20=0 (x-2m)^2 (y m)^2=5m^2-20m 20 (x-2m)^2 (y m)^2=5(m-2)^2 (4-2m)^2 (-2 m)^2=16-16m 4m^2 4-4m m^2=20-20m-5m^2=5(m-2)^2 恒过(4,-2)点
    2018-03-08 10:18:10
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