Equation (Cartesian): ((x-a)/c)^2 - ((y-b)/d)^2 = 1 ''
Equation (Cartesian): ((x-a)/c)^2 - ((y-b)/d)^2 = -1 ''
Equation (Cartesian): y-a = c/(x-b) ''
Equation (Cartesian): y-a = -c/(x-b) ''
Equation (Polar): r^2 = a sec 2t ''
Equation (Polar): r^2 = -a sec 2t ''
Equation (Polar): r^2 = a csc 2t ''
Equation (Polar): r^2 = -a csc 2t ''