焦点-9x^2+y^2+54x-117=0

解答

焦点

- 9 x^{2} + y^{2} + 54 x - 117 = 0

(3, 210), (3, - 210)

求解步骤

(h, k + c), (h, k - c)

计算双曲线性质

- 9 x^{2} + y^{2} + 54 x - 117 = 0 :

上下开口双曲线，

(h, k) = (3, 0), a = 6, b = 2

(3, 0 + c), (3, 0 - c)

计算

c :

c = 6^{2} + 2^{2} : 210

(3, 0 + 210), (3, 0 - 210)

整理后得

(3, 210), (3, - 210)

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