椭圆方程为:x²/24+y²/6=1.
由题意,可知直线L方程为y=(1/p)x-2,椭圆方程可化为x²/4+y²=b²,
联立两方程,得(1/p²+1/4)x²-(4/p)x+4-b²=0,
设A(x1,y1),B(x2,y2),于是x1+x2=(4/p)/(1/p²+1/4)①,x1x2=(4-b²)/(1/p²+1/4)②;
则k1+k2=y1/x1+y2/x2=(y1x2+y2x1)/(x1x2)=[(2/p)x1x2-(x1+x2)]/(x1x2)=4k=4/p.
【其中y1=(1/p)x1-2,y2=(1/p)x2-2】
即(x1+x2)+(2/p)x1x2=0③,将①②式代入③式,即可化简得b²=6.
于是椭圆的方程为x²/24+y²/6=1.
