焦点 ((x-1)^2)/4-(y+3)^2=1

解答

焦点

\frac{( x - 1 ) ^{2}}{4} - (y + 3)^{2} = 1

(1 + 5, - 3), (1 - 5, - 3)

求解步骤

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

计算双曲线性质

\frac{( x - 1 ) ^{2}}{4} - (y + 3)^{2} = 1 :

左右开口双曲线，

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

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

计算

c :

c = 2^{2} + 1^{2} : 5

(1 + 5, - 3), (1 - 5, - 3)

f oc i 144 y^{2} - 25 x^{2} = 3600

f oc i \frac{y ^{2}}{25} - \frac{x ^{2}}{39} = 1

f oc i 16 y^{2} - 25 x^{2} = 1600

f oc i \frac{( x - 1 ) ^{2}}{9} - \frac{( y - 2 ) ^{2}}{16} = 1

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