椭圆方程,求方法
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/14 05:26:38
椭圆方程,求方法
![](http://img.wesiedu.com/upload/1/e2/1e2ad40278f1fbc6332bc555033c842f.jpg)
![](http://img.wesiedu.com/upload/1/e2/1e2ad40278f1fbc6332bc555033c842f.jpg)
![椭圆方程,求方法](/uploads/image/z/18509030-62-0.jpg?t=%E6%A4%AD%E5%9C%86%E6%96%B9%E7%A8%8B%2C%E6%B1%82%E6%96%B9%E6%B3%95%26nbsp%3B)
假定是第3题, 显然∆AOB与∆OFC相似.
AO = a, OB = b, OF = c
C(c, t), t >0: c²/a² + t²/b² = 1
t² = b²(1 - c²/a²) = b²(a² - c²)/a² = (b²)²/a²
t = b²/a
AO/OB=OF/FC
a/b = c/(b²/a)
b = c = 3
a² = b² + c² = 18
x²/18 + y²/9 = 1
AO = a, OB = b, OF = c
C(c, t), t >0: c²/a² + t²/b² = 1
t² = b²(1 - c²/a²) = b²(a² - c²)/a² = (b²)²/a²
t = b²/a
AO/OB=OF/FC
a/b = c/(b²/a)
b = c = 3
a² = b² + c² = 18
x²/18 + y²/9 = 1