(e2−1)/a\left(e^{2}-1\right) / \sqrt{ } a(e2−1)/a
(e2−1)\left(e^{2}-1\right)(e2−1)
(1−e2)/a\left(1-e^{2}\right) / \sqrt{a}(1−e2)/a
(1−e2)/a\left(1-e^{2}\right) / a(1−e2)/a
