左焦点F坐标为(-2√2,0).设直线斜率为k,方程为y=k(x+2√2),代入x^2/9+y^2=1并消去y得：(1+9k²)x²+36√2k²x+9(8k²-1)=0,判别式△=36²×2k^4-36(1+9k²) (8k²-1)=36[72 k^4-(72 k^4...