焦点 ((y+3)^2)/9-((x-1)^2)/(18)=1

解答

焦点

\frac{( y + 3 ) ^{2}}{9} - \frac{( x - 1 ) ^{2}}{18} = 1

(1, - 3 + 33), (1, - 3 - 33)

求解步骤

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

计算双曲线性质

\frac{( y + 3 ) ^{2}}{9} - \frac{( x - 1 ) ^{2}}{18} = 1 :

上下开口双曲线，

(h, k) = (1, - 3), a = 3, b = 32

(1, - 3 + c), (1, - 3 - c)

计算

c :

c = 3^{2} + (32)^{2} : 33

(1, - 3 + 33), (1, - 3 - 33)