# Ellipse Calculator

This calculator will find either the equation of the ellipse from the given parameters or the center, foci, vertices (major vertices), co-vertices (minor vertices), (semi)major axis length, (semi)minor axis length, area, circumference, latera recta, length of the latera recta, focal parameter, focal length (distance), eccentricity, linear eccentricity, directrices, x-intercepts, y-intercepts, domain, and range of the entered ellipse. Also, it will graph the ellipse. Steps are available.

Related calculators: Parabola Calculator, Circle Calculator, Hyperbola Calculator, Conic Section Calculator

## Your Input

**Find the center, foci, vertices, co-vertices, major axis length, semi-major axis length, minor axis length, semi-minor axis length, area, circumference, latera recta, length of the latera recta, focal parameter, focal length, eccentricity, linear eccentricity, directrices, x-intercepts, y-intercepts, domain, and range of the ellipse $$$4 x^{2} + 9 y^{2} = 36$$$.**

## Solution

The equation of an ellipse is $$$\frac{\left(x - h\right)^{2}}{a^{2}} + \frac{\left(y - k\right)^{2}}{b^{2}} = 1$$$, where $$$\left(h, k\right)$$$ is the center, $$$a$$$ and $$$b$$$ are the lengths of the semi-major and the semi-minor axes.

Our ellipse in this form is $$$\frac{\left(x - 0\right)^{2}}{9} + \frac{\left(y - 0\right)^{2}}{4} = 1$$$.

Thus, $$$h = 0$$$, $$$k = 0$$$, $$$a = 3$$$, $$$b = 2$$$.

The standard form is $$$\frac{x^{2}}{3^{2}} + \frac{y^{2}}{2^{2}} = 1$$$.

The vertex form is $$$\frac{x^{2}}{9} + \frac{y^{2}}{4} = 1$$$.

The general form is $$$4 x^{2} + 9 y^{2} - 36 = 0$$$.

The linear eccentricity is $$$c = \sqrt{a^{2} - b^{2}} = \sqrt{5}$$$.

The eccentricity is $$$e = \frac{c}{a} = \frac{\sqrt{5}}{3}$$$.

The first focus is $$$\left(h - c, k\right) = \left(- \sqrt{5}, 0\right)$$$.

The second focus is $$$\left(h + c, k\right) = \left(\sqrt{5}, 0\right)$$$.

The first vertex is $$$\left(h - a, k\right) = \left(-3, 0\right)$$$.

The second vertex is $$$\left(h + a, k\right) = \left(3, 0\right)$$$.

The first co-vertex is $$$\left(h, k - b\right) = \left(0, -2\right)$$$.

The second co-vertex is $$$\left(h, k + b\right) = \left(0, 2\right)$$$.

The length of the major axis is $$$2 a = 6$$$.

The length of the minor axis is $$$2 b = 4$$$.

The area is $$$\pi a b = 6 \pi$$$.

The circumference is $$$4 a E\left(\frac{\pi}{2}\middle| e^{2}\right) = 12 E\left(\frac{5}{9}\right)$$$.

The focal parameter is the distance between the focus and the directrix: $$$\frac{b^{2}}{c} = \frac{4 \sqrt{5}}{5}$$$.

The latera recta are the lines parallel to the minor axis that pass through the foci.

The first latus rectum is $$$x = - \sqrt{5}$$$.

The second latus rectum is $$$x = \sqrt{5}$$$.

The length of the latera recta is $$$\frac{2 b^{2}}{a} = \frac{8}{3}$$$.

The first directrix is $$$x = h - \frac{a^{2}}{c} = - \frac{9 \sqrt{5}}{5}$$$.

The second directrix is $$$x = h + \frac{a^{2}}{c} = \frac{9 \sqrt{5}}{5}$$$.

The x-intercepts can be found by setting $$$y = 0$$$ in the equation and solving for $$$x$$$ (for steps, see intercepts calculator).

x-intercepts: $$$\left(-3, 0\right)$$$, $$$\left(3, 0\right)$$$

The y-intercepts can be found by setting $$$x = 0$$$ in the equation and solving for $$$y$$$: (for steps, see intercepts calculator).

y-intercepts: $$$\left(0, -2\right)$$$, $$$\left(0, 2\right)$$$

The domain is $$$\left[h - a, h + a\right] = \left[-3, 3\right]$$$.

The range is $$$\left[k - b, k + b\right] = \left[-2, 2\right]$$$.

## Answer

**Standard form: $$$\frac{x^{2}}{3^{2}} + \frac{y^{2}}{2^{2}} = 1$$$A.**

**Vertex form: $$$\frac{x^{2}}{9} + \frac{y^{2}}{4} = 1$$$A.**

**General form: $$$4 x^{2} + 9 y^{2} - 36 = 0$$$A.**

**First focus-directrix form: $$$\left(x + \sqrt{5}\right)^{2} + y^{2} = \frac{5 \left(x + \frac{9 \sqrt{5}}{5}\right)^{2}}{9}$$$A.**

**Second focus-directrix form: $$$\left(x - \sqrt{5}\right)^{2} + y^{2} = \frac{5 \left(x - \frac{9 \sqrt{5}}{5}\right)^{2}}{9}$$$A.**

**Graph: see the graphing calculator.**

**Center: $$$\left(0, 0\right)$$$A.**

**First focus: $$$\left(- \sqrt{5}, 0\right)\approx \left(-2.23606797749979, 0\right)$$$A.**

**Second focus: $$$\left(\sqrt{5}, 0\right)\approx \left(2.23606797749979, 0\right)$$$A.**

**First vertex: $$$\left(-3, 0\right)$$$A.**

**Second vertex: $$$\left(3, 0\right)$$$A.**

**First co-vertex: $$$\left(0, -2\right)$$$A.**

**Second co-vertex: $$$\left(0, 2\right)$$$A.**

**Major axis length: $$$6$$$A.**

**Semi-major axis length: $$$3$$$A.**

**Minor axis length: $$$4$$$A.**

**Semi-minor axis length: $$$2$$$A.**

**Area: $$$6 \pi\approx 18.849555921538759$$$A.**

**Circumference: $$$12 E\left(\frac{5}{9}\right)\approx 15.86543958929059$$$A.**

**First latus rectum: $$$x = - \sqrt{5}\approx -2.23606797749979$$$A.**

**Second latus rectum: $$$x = \sqrt{5}\approx 2.23606797749979$$$A.**

**Length of the latera recta: $$$\frac{8}{3}\approx 2.666666666666667$$$A.**

**Focal parameter: $$$\frac{4 \sqrt{5}}{5}\approx 1.788854381999832$$$A.**

**Eccentricity: $$$\frac{\sqrt{5}}{3}\approx 0.74535599249993$$$A.**

**Linear eccentricity: $$$\sqrt{5}\approx 2.23606797749979$$$A.**

**First directrix: $$$x = - \frac{9 \sqrt{5}}{5}\approx -4.024922359499621$$$A.**

**Second directrix: $$$x = \frac{9 \sqrt{5}}{5}\approx 4.024922359499621$$$A.**

**x-intercepts: $$$\left(-3, 0\right)$$$, $$$\left(3, 0\right)$$$A.**

**y-intercepts: $$$\left(0, -2\right)$$$, $$$\left(0, 2\right)$$$A.**

**Domain: $$$\left[-3, 3\right]$$$A.**

**Range: $$$\left[-2, 2\right]$$$A.**