焦点 ((y-2)^2}{14}-\frac{(x+6)^2)/3 =4

解答

焦点

\frac{( y - 2 ) ^{2}}{14} - \frac{( x + 6 ) ^{2}}{3} = 4

(- 6, 2 + 217), (- 6, 2 - 217)

求解步骤

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

计算双曲线性质

\frac{( y - 2 ) ^{2}}{14} - \frac{( x + 6 ) ^{2}}{3} = 4 :

上下开口双曲线，

(h, k) = (- 6, 2), a = 214, b = 23

(- 6, 2 + c), (- 6, 2 - c)

计算

c :

c = (214)^{2} + (23)^{2} : 217

(- 6, 2 + 217), (- 6, 2 - 217)

f oc i 3 x^{2} - 13 y^{2} - 30 x + 52 y = 16

f oc i 4 x^{2} + 9 y^{2} + 3 x - 18 y^{2} + 37 = 0

f oc i 9 x^{2} - 2 y^{2} = 18

f oc i \frac{x ^{2}}{49} - \frac{y ^{2}}{36} = 1

f oc i 36 y^{2} - 4 x^{2} = 144