Question

已知椭圆x^2/9 +y^2 =1,过左焦点F作倾斜角π/6 的直线交椭圆于A,B亮点,求弦AB的长

Answer 1

说倾角都是指直线在x轴上方部分和x轴正方向的夹角。
F(负根号8，0）k=根号3/3，
AB={根号（1+k^2)}{(x1+x2)^2-4*x1*x2}
x^2/9+y2^2=1
y=根号3/3（x+根号8）
消去y得：x1+x2= x1*x2= 带入AB中即可

Answer 2

Many life's failures are people who did not realize how close they were to success when they gave upNever gave up `