foci of ellipse

Equation of Ellipse in Standard Form The equation of ellipse in standard form referred to its principal axes along the coordinate axes is \(x^2\over a^2\) + \(y^2\over b^2\) = 1, where a > b & \(b^2\) = \(a^2(1 – e^2)\) \(\implies\) \(a^2\) – \(b^2\) = \(a^2e^2\). where e = eccentricity (0 < e < 1)