按椭圆定义,F₁A + F₂A = 2a,F₁F₂ = 2c
△AF1F2的周长为6 = 2a + 2c
a + c = a + √(a² - b²) = 3
a = (b² + 9)/6
a² - b² = (b² - 9)²/36
e² = (a² - b²)/a² = (b² - 9)²/(b² + 9)²
e = |b² - 9|/(b² + 9)
36x²/(b² + 9)² + y²/b² = 1
按椭圆定义,F₁A + F₂A = 2a,F₁F₂ = 2c
△AF1F2的周长为6 = 2a + 2c
a + c = a + √(a² - b²) = 3
a = (b² + 9)/6
a² - b² = (b² - 9)²/36
e² = (a² - b²)/a² = (b² - 9)²/(b² + 9)²
e = |b² - 9|/(b² + 9)
36x²/(b² + 9)² + y²/b² = 1