Can the semi - major and semi - minor axes of an ellipse be time dependent? More specifically, can you have time dependent semi - major and semi - minor axes present in the standard form of the ellipse? I have an equation of the form [tex]\frac{(\xi ^{1}(t))^{2} }{a^{2}} + \frac{(\xi ^{2}(t))^{2}}{b^{2}} = 1 [/tex] where [itex]\xi ^{\alpha }[/itex] are components of a separation vector, [itex]a^{2} = [2 + \frac{1}{2}sin^{2}\omega t](\xi ^{1}(0))^{2}[/itex], and [itex]b^{2} = [2 + \frac{1}{2}sin^{2}\omega t](\xi ^{2}(0))^{2}[/itex] but I don't know if the standard form can actually have time dependent semi - major and minor axes.(adsbygoogle = window.adsbygoogle || []).push({});

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Simple Ellipse Question

**Physics Forums | Science Articles, Homework Help, Discussion**