x2a2−y2b2=1\dfrac{x^2}{a^2} - \dfrac{y^2}{b^2} = 1a2x2−b2y2=1: foci (±c,0)(\pm c, 0)(±c,0) where c2=a2+b2c^2 = a^2 + b^2c2=a2+b2; asymptotes y=±baxy = \pm \tfrac{b}{a} xy=±abx.