Help 27,28
27. 9y^2 - 16x^2 = 144
Divide through by 144 to get to this form
y^2 - x^2 = 1
___ ____
16 9
The center is (0, 0)
The foci are given by
(0, ±√ [ 4^2 + 3^2 ] =
(0, ±√25 ) =
(0, ±5)
28. The correct equation is
y^2 - x^2
___ ___ = 1
144 25