\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}} = 1

r = \frac{a(1 − e^{2})}{1 + e cos θ}

b^{2} = a^{2}(1 − e^{2})

r = a(1 − e cos E)

tan(\frac{v}{2} ) = \sqrt{\frac{1 + e}{1 − e}} tan(\frac{E}{2} )

n = \frac{2π}{P}

E − e sin(E) = (t − T)n

E = M + ∑_{k=1}^{∞} \frac{2}{k} J_{k}(ke) sin(kM)