\(\frac{x-x_c}{a^2} + \frac{y-y_c}{b^2} = \pm\hspace{1mm}1\) (For Real and Imaginary Ellipses having Major Axes Parallel to \(X\)-Axis)...(1)
\(\frac{y-y_c}{a^2} + \frac{x-x_c}{b^2} = \pm\hspace{1mm}1\) (For Real and Imaginary Ellipses having Major Axes Parallel to \(Y\)-Axis)...(2)
The following gives the Formulae for finding out Various Parameters of Ellipse given the Standard Coordinate Equation
Coordinates of the Center: \((x_c,y_c)\)
Length of Semi-Major Axis: \(a\)
Length of Major Axis: \(L=2a\)
Length of Semi-Minor Axis: \(b\)
Length of Minor Axis: \(l=2b\)
Distance Between 2 Foci: \(F=\sqrt{L^2-l^2}=2c=2\sqrt{a^2-b^2}\)
Eccentricity \(e\) : \(\frac{F}{L}=\frac{c}{a}\)
Length for Latus Rectum : \(\frac{l^2}{L}=\frac{2b^2}{a}\)
If Major Axis is Parallel to \(X\)-Axis then Angular Orientation: 0° Coordinates of the 2 Foci: \((x_c + c,y_c),\hspace{.3cm}(x_c - c,y_c)\) Coordinates of the 2 Vertices: \((x_c + a,y_c),\hspace{.3cm}(x_c - a,y_c)\) Coordinates of the 2 Co-Vertices: \((x_c,y_c+b),\hspace{.3cm}(x_c,y_c-b)\) Equation of Major Axis: \(y=y_c\) Equation of Minor Axis: \(x=x_c\) Equation of 2 Directrices: \(x=x_c+\frac{L^2}{2F},\hspace{.3cm} x=x_c-\frac{L^2}{2F}\) OR \(x=x_c+\frac{a^2}{c},\hspace{.3cm} x=x_c-\frac{a^2}{c}\) Equation of 2 Latus Recta: \(x=x_c+c,\hspace{.5cm} x=x_c-c\) Coordinates of Points of Intersection of Latus Rectum-1 and Ellipse: \((x_c+c,y_c+\frac{l^2}{2L})\),\((x_c+c,y_c-\frac{l^2}{2L})\) OR \((x_c+c,y_c+\frac{b^2}{a})\),\((x_c+c,y_c-\frac{b^2}{a})\) Coordinates of Points of Intersection of Latus Rectum-2 and Ellipse: \((x_c-c,y_c+\frac{l^2}{2L})\),\((x_c-c,y_c-\frac{l^2}{2L})\) OR \((x_c-c,y_c+\frac{b^2}{a})\),\((x_c-c,y_c-\frac{b^2}{a})\)
If Major Axis is Parallel to \(Y\)-Axis then Angular Orientation: 90° Coordinates of the 2 Foci: \((x_c,y_c + c),\hspace{.3cm}(x_c,y_c - c)\) Coordinates of the 2 Vertices: \((x_c,y_c + a),\hspace{.3cm}(x_c,y_c - a)\) Coordinates of the 2 Co-Vertices: \((x_c+b,y_c),\hspace{.3cm}(x_c-b,y_c)\) Equation of Major Axis: \(x=x_c\) Equation of Minor Axis: \(y=y_c\) Equation of 2 Directrices: \(y=y_c+\frac{L^2}{2F},\hspace{.3cm} y=y_c-\frac{L^2}{2F}\) OR \(y=y_c+\frac{a^2}{c},\hspace{.3cm} y=y_c-\frac{a^2}{c}\) Equation of 2 Latus Recta: \(y=y_c+c,\hspace{.5cm} y=y_c-c\) Coordinates of Points of Intersection of Latus Rectum-1 and Ellipse: \((x_c+\frac{l^2}{2L},y_c+c)\),\((x_c-\frac{l^2}{2L},y_c+c)\) OR \((x_c+\frac{b^2}{a},y_c+c)\),\((x_c-\frac{b^2}{a},y_c+c)\) Coordinates of Points of Intersection of Latus Rectum-2 and Ellipse: \((x_c+\frac{l^2}{2L},y_c-c)\),\((x_c-\frac{l^2}{2L},y_c-c)\) OR \((x_c+\frac{b^2}{a},y_c-c)\),\((x_c-\frac{b^2}{a},y_c-c)\)