L为双曲线,渐近线为x±2y=0,L1:x-3y=0,L1被L所截弦长为8*根号3/3
问题描述:
L为双曲线,渐近线为x±2y=0,L1:x-3y=0,L1被L所截弦长为8*根号3/3
答
因渐近线是x±2y=0,则设双曲线方程是x²-4y²=m,与直线x-3y=0联立,得:x²-(4/9)x²=m,即:(5/9)x²-m=0.弦长是|AB|=√(1+k²)|x1-x2|=8√3/3 ==>> k=1/3,x1、x2是方程(5/9)x²-...