解析几何中求切线长最大值
问题描述：
解析几何中求切线长最大值
（前略）E:(x^2)/4+y^2=1,设直线l与圆C:x^2+y^2=R^2(1
数学人气：528 ℃时间：2020-10-02 04:47:29
优质解答
设B(a,b)则AB:ax/4+yb=1设A(m,n)则AB:xm/R²+yn/R²=1且有a=4m/R²,b=n/R²得4m²+n²=R^4m²+n²=R²故|AB|²=(a-m)²+(b-n)²=R²+(16m²+n²)/R^4-...
我来回答
类似推荐
答
设B(a,b)则AB:ax/4+yb=1设A(m,n)则AB:xm/R²+yn/R²=1且有a=4m/R²,b=n/R²得4m²+n²=R^4m²+n²=R²故|AB|²=(a-m)²+(b-n)²=R²+(16m²+n²)/R^4-...