焦点 x^2-(y^2)/9 =1

解答

焦点

x^{2} - \frac{y ^{2}}{9} = 1

(10, 0), (- 10, 0)

求解步骤

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

计算双曲线性质

x^{2} - \frac{y ^{2}}{9} = 1 :

左右开口双曲线，

(h, k) = (0, 0), a = 1, b = 3

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

计算

c :

c = 1^{2} + 3^{2} : 10

(0 + 10, 0), (0 - 10, 0)

整理后得

(10, 0), (- 10, 0)

f oc i 10 x^{2} - 25 y^{2} = 100

f oc i \frac{x ^{2}}{4} - \frac{y ^{2}}{1} = 1

f oc i 12 x^{2} - 3 y^{2} = 36

f oc i \frac{y ^{2}}{4} - \frac{x ^{2}}{36} = 1

f oc i 64 y^{2} - 36 x^{2} = 2304