焦点 ((x-2)^2)/9-((y+1)^2)/5 =1

解答

焦点

\frac{( x - 2 ) ^{2}}{9} - \frac{( y + 1 ) ^{2}}{5} = 1

(2 + 14, - 1), (2 - 14, - 1)

求解步骤

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

计算双曲线性质

\frac{( x - 2 ) ^{2}}{9} - \frac{( y + 1 ) ^{2}}{5} = 1 :

左右开口双曲线，

(h, k) = (2, - 1), a = 3, b = 5

(2 + c, - 1), (2 - c, - 1)

计算

c :

c = 3^{2} + 5^{2} : 14

(2 + 14, - 1), (2 - 14, - 1)