Question

What is the equation of directrix formula of an ellipse along the y axis?

Answer 1

Therefore, any point that satisfies equation (1), i.e. x2/a2 + y2/b2 = 1, lies on the ellipse. Also, the equation of an ellipse with centre of the origin and major axis along the x-axis is: x2/a2 + y2/b2 = 1.