SOLUTION: Find the foci of a hyperbola with the equation 9y2 - 72y - 16x2 - 64x - 64 = 0.

Algebra ->  Coordinate-system -> SOLUTION: Find the foci of a hyperbola with the equation 9y2 - 72y - 16x2 - 64x - 64 = 0.       Log On


   



Question 145227: Find the foci of a hyperbola with the equation 9y2 - 72y - 16x2 - 64x - 64 = 0.

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the foci of a hyperbola with the equation 9y2 - 72y - 16x2 - 64x - 64 = 0.
-------------------
9(y^2 - 8y + 16) - 16(x^2 -4x + 4) = 64+9*16-4*16
---------
9(y -4)^2 - 16(x - 2)^2 = 144
-------
[(y -4)^2/16] - [(x - 2)^2/4] = 1
---------
Center at (2,4); a = 4 ; b = 2 ; therefore c = sqrt(a^2+b^2) = 2sqrt(5)
Focus at (2, 4+2sqrt(5)) and (2,4-2sqrt(5))
=============
Cheers,
Stan H.