The equation of ellipse are [tex] \frac{x^{2}}{b^{2}}+\frac{y^{2}}{a^{2}}=1 [/tex] for [tex] b\geq a [/tex] and [tex] \frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1 [/tex] for [tex] b\geq a [/tex]
One thing is changed between the two equations that is the placement of [tex] a^{2} [/tex] and [tex] b^{2} [/tex]. The [tex] a^{2} [/tex] always goes with the variable whose axis parallel the wider direction of the ellipse and [tex] b^{2} [/tex] always goes with the variable whose axis parallel the narrower direction.
