Ellipse Formula

Ellipse Formula

The location of all the points on a plane whose sum of the distances from two fixed points in the plane is constant is known as an ellipse. The foci (singular focus), which are fixed locations that are encircled by the curve, are known. Directrix is the fixed line, and the eccentricity of the ellipse is the constant ratio. The Ellipse Formula eccentricity, which is represented by the letter “e,” shows how long it is.

The area of an ellipse is determined by its major axis and minor axis. Ellipses have an oval form. The area of an ellipse is equal to ab, where a and b are the lengths of the ellipse’s semi-major and semi-minor axes. The Ellipse Formula resembles other unbounded and open conic sections, such as the parabola and the hyperbola.

The collection of all points on an XY-plane whose distance from two fixed points (referred to as foci) adds up to a constant number is an Ellipse Formula if we speak in terms of locus.

One of the conic sections created when a plane cuts a cone at an angle with its base is the ellipse. If the plane parallel to the base intersects the cone, a circle is formed.

A two-dimensional form in geometry known as an ellipse is defined along its axes. When a plane intersects a cone at an angle to the base of the cone, an ellipse is created.

It centres on two things. For every point on the curve, the total distance from the focus point is a fixed amount.

Since the foci of an Ellipse Formula are always in the same location—the circle’s centre—circles are also ellipses.

Consider point P at the main axis’s extreme. The sum of the distances between point P and the foci is thus,

F1P+F2P = F1O+OP+F2P=c+a+(a-c)=2a

Next, choose a point Q at one of the minor axes’ ends. Currently, the total distance between Q and the foci is,

(b2 + c2) + (b2 + c2) = 2 is the formula for F1Q and F2Q.

Points P and Q are previously known to be on the ellipse. Therefore, we have, by definition

2√ (b2 + c2) = 2a

So (b2 + c2) = a.

such as c2 = a2 – b2 or a2 = b2 + c2.

The ellipse’s equation is as follows.

c2= a2 – b2

What is an Ellipse?

An ellipse is a closed-shape structure on a two-dimensional plane, as is common knowledge. It, therefore, covers space in a 2D plane. The area of the ellipse is hence its delimited region. Since the ellipse differs in shape from a circle, so will the Ellipse Formula for calculating its area.

Ellipse Formula is a fundamental component of a conic section and has many characteristics with a circle. An ellipse is oval in shape as opposed to a circle. An ellipse is a shape with an eccentricity less than one that symbolises a group of points whose distances from its two foci are added up to a fixed number. The shape of an egg in two dimensions and the running track in a sports arena are two straightforward examples of the Ellipse Formula in daily life.

Here, the goals are to understand the concept of an Ellipse Formula, how the Ellipse Formula equation is derived, and the several conventional forms in which the Ellipse Formula is expressed. One can access information on the topic of the Ellipse Formula from the Extramarks website.

Ellipse Definition

In Mathematics, an ellipse is the location of points in a plane so that their separation from a fixed point has a set ratio of “e” to their separation from a fixed line (less than 1). The conic section, which is the intersection of a cone with a plane that does not intersect the base of the cone, includes the Ellipse Formula. The eccentricity of the Ellipse Formula is symbolised by the constant ratio “e,” the fixed point is known as the focus, and the fixed line is known as the directrix (d).

The location of points in a plane whose sum of separations from two fixed points equals a constant value is known as an Ellipse Formula. In the Ellipse Formula, two fixed points are referred to as their foci.

Ellipse Equation

The Extramarks website and mobile applications both provide the ellipse equation and the Ellipse Formula. It is recommended to refer to the Ellipse Formula notes available on Extramarks. The semi-major axis in this case is a, while the semi-minor axis is b. The x-axis is the transverse axis, the y-axis is the conjugate axis, and the origin is the centre of the ellipse for this equation.

Ellipse Formula is a geometric form in the conic section where each point is equal to the entire distance between the two fixed points. The resource Previous Year Questions with solutions on Ellipse Formula is crucial for JEE candidates. Students will encounter questions from prior JEE exams while studying Ellipse Formula. Extramarks provides solutions on its website along with  PDFs for offline study in an effort to aid students in improving their problem-solving abilities. These answers on the Ellipse Formula will make it easier for students to comprehend the concepts of the Ellipse Formula. To aid students in their test preparation and to dispel any lingering worries, Extramarks offers chapter-by-chapter past years’ problems with solutions. Notes on the Ellipse Formula may be acquired by students for a better understanding of the topic.

An ellipse is a two-dimensional form in geometry that may be characterised along its axes. An Ellipse Formula is formed when a plane intersects a cone at an angle to the base of the cone. There are two points of focus. For every location along the curve, the sum of the two distances to the focal point remains constant. An Ellipse Formula with all of its foci at the circle’s centre is also referred to as a circle.

Parts of an Ellipse

It is a plane curve that encircles two focus points in such a way that the sum of the two distances from each point on the curve to the focal point is constant. In other terms, the ellipse is the region on the plane where the total of the distances between two fixed points, or foci, is always constant. The circle with all points fixedly spaced from the centre has been shown to students. An Ellipse Formula resembles a compressed circle.

A conic portion could have been present. The junction of the cone with the plane is traced by a plane curve.


The fixed points of the Ellipse Formula that are located on the principal axis are the foci, sometimes referred to as the focal point. They are represented by F and F’ in figure 1.1.

Major Axis

The primary axis of an Ellipse Formula is its largest diameter. It runs from one side of the elliptical to the middle and out the other. It is the ellipse’s broader region’s diameter. In other words, the main axis goes through the centre and both foci and is congruent with the major diameter. The line segment overleaf “AA’,” which has a length of 2a, is the primary axis of the ellipse in figure 1.1.

Minor Axis

It has the ellipse’s smallest diameter and traverses the centre to go from one side to the other. It is the width of the ellipse’s narrowest portion. Students may alternatively define the minor axis as the perpendicular bisector of the major axis, which is a line that splits another line into two halves. In figure 1.1, the line segment overlined “BB’,” which has a length of 2 b, serves as the minor axis of the ellipse.

Lens Length

The line segment overlined with the letters “FF” in figure 1.1 has a length of 2c and serves as the ellipse’s focal length.


The location where the axes connect is where the ellipse’s centre is located. It is the ellipse’s symmetry centre.


The vertices of the ellipse are the points of intersection of the ellipse with the axes. They are denoted by A, A’, B, and B’.

Focal Radii

The line segments that join a point on the ellipse with both foci are referred to as the focal radii of the ellipse. They are denoted by PF and PF’.

Semi-Major Axis

Half of the major axis is known as the semi-major axis. The semi-major axis is the line segment that runs from the centre of the ellipse, through a focus, and to a vertex of the ellipse.

Miniature Axis

The semi-minor axis is the other half of the minor axis. The line segment that goes from the ellipse’s centre to a vertex and is perpendicular to the semi-major axis is known as the semi-minor axis. It is b length.

An ellipse is more precisely described as a circle if a = b.

Standard Equation of an Ellipse

The equation for an Ellipse Formula is the same as the equation for a circle. The standard form equation of an ellipse with the main axis parallel to the y-axis and a centre (0,0) is presented.

Derivation of Ellipse Equation

The Ellipse Formula may be obtained from its fundamental definition as follows: A point’s location is called an ellipse when the sum of its distances from two fixed places is a defined amount. The foci are F and F’, and the fixed point is P(x, y). The equation then becomes PF + PF’ = 2a. Students now obtain the Ellipse Formula as it is given on the Extramarks website and mobile application after further substitutions and simplification.

Ellipse Formulas

An Ellipse Formula is the collection of all points in a plane whose total of their separations from two fixed points in the plane is constant. The foci of the ellipse are these two fixed locations. The centre of the ellipse is found at the midpoint of the line segment that connects the two focal points.

Perimeter of an Ellipse Formulas

A planar curve with two focus points is called an ellipse when the sum of the distances from each point on the curve to the two focal points remains constant. Two axes are present in an ellipse. They are the major and minor axes, respectively.

The formulas are as follows:

  • Area of the Ellipse Formula
  • Perimeter of the Ellipse Formula
  • Equation of the Ellipse Formula in Standard Form

Area of Ellipse Formula

The Area of Ellipse Formula is given on the Extramarks website and mobile application that students can refer to before their examinations. It is very important for students to make sure they follow the comprehensive Ellipse Formula solutions provided by the Extramarks experts to succeed in the examinations with high scores.

Eccentricity of an Ellipse Formula

Conic section eccentricity is a measure of how rounded the conic section is. More eccentric behaviour is associated with less spherical behaviour, while the opposite is true. The letter “e. e.” stands in for it. The eccentricity of the Ellipse Formula is defined as the ratio of the distance between the focus and a point on the plane to the vertex and only that point. A circle’s eccentricity is 0e1.

The measurement of the Ellipse Formula curved feature is referred to as its eccentricity. The eccentric is always bigger than one for an ellipse. (e < 1). Eccentricity is the ratio between the focus and one elliptic’s end’s distance from the centre. Eccentricity e = c/a if the focus’s distance from the ellipse’s centre is “c” and the end of the ellipse’s distance from the centre is “a.”

Latus Rectum of Ellipse Formula

The ellipse x2/a2 + y2/b2 = 1 has a latus rectum that is 2b2/a long.

The centre of the ellipse is at

Ellipses typically has two focus points and two latus recta as a result.

Formula for Equation of an Ellipse

The Latin words latus, which means “side,” and rectum, which means “straight,” are combined to form the English phrase “latus rectum” in the conic section. The latus rectum is the chord that crosses the focus and is perpendicular to the directrix. The terminal point of the latus rectum is situated on the curve. Half of the latus rectum makes up the semi-latus rectum.

An Ellipse Formula latus rectum is a line that passes through its foci and is drawn perpendicular to its transverse axis. The focal chord, which traces a line parallel to the ellipse’s directrix, is located in the latus rectum of an Ellipse Formula. The ellipse has two foci and hence two latus rectums. The Ellipse Formula latus rectum can be understood by referring to the Extramarks website or mobile application.

Formula for Equation of an Ellipse

An Ellipse Formula that reads (xh)2a2+(yk)2b2=1. The largest of a and b is the major radius, and the smaller is the minor radius. The centre is at (h, k).

Properties of an Ellipse

The following list includes the many characteristics of an Ellipse Formula:

  • A plane crossing a cone at the angle of its base results in an Ellipse Formula.
  • Every Ellipse Formula has a centre, a major and minor axis, and two foci.
  • The total distances between any two foci and any point on the Ellipse Formula equals a fixed amount.
  • All ellipses have eccentricity values that are less than one.

How to Draw an Ellipse?

  1. Draw the main axis very gently to determine the size.
  2. Determine the precise location of the major axis’s centre and draw a second line perpendicular to it, with the distance above and below the major axis being equal. This is the minor axis, which will also define the ellipse’s pitch.
  3. Draw the curved ends along the main axis gently. Draw in the remaining ellipse above and below the major axis once both curves are symmetrical, making sure that the curves touch the top and bottom of the minor axis line. The axis lines will be divided into four equal-sized, mirrored quadrants.
  4. After making any necessary symmetry corrections, draw the final, darker lines.

The amount of area included within an ellipse is referred to as its area. Alternatively, the total number of unit squares that may fit inside an ellipse represents its area. Students may have noticed a variety of ellipse-shaped objects in their everyday life, such as a cricket pitch, a badminton racket, a planet’s orbit, etc.

The semi-major axis length, semi-minor axis length, and the product determine the ellipse’s area. Students can learn more about this shape by talking about its area, the ellipse’s formula for area, and some examples with answers to frequently asked questions.

The region or area that an ellipse covers in two dimensions are known as its area. Square units like in2, cm2, m2, yd2, ft2, etc. are used to express the area of an ellipse. An ellipse is a 2-D form that is created by joining all the points on the plane that are always at the same distance from the two fixed points. The fixed locations are known as ellipse foci. The two foci are F1 and F2. Because an ellipse is not a perfect circle, there is a variation in the distance between its centre and its points on the circumference. An ellipse, therefore, has two radii. The major axis of the ellipse is the name of the chord in the ellipse that is the longest.

Graph of Ellipse

The main radius and minor radius, as well as the ellipse’s centre, determine the graph in its entirety. If the ellipse’s equation is written in standard form, (xh)2a2+(ykh)2b2=1, the centre, orientation, major radius, and minor radius are immediately discernible.

Ellipse Formula components include:

  • Two axes, known as the “major” and “minor,” which run along the x and y axes, serve to differentiate ellipses:
  • The main axis, which spans the ellipse’s centre from one end to the other at its widest point, has the largest diameter.
  • The minor axis, which passes through the centre of an ellipse at its narrowest point, has the smallest diameter. The semi-major axis makes up half of the major axis, while the semi-minor axis makes up half of the minor axis.
  • Eccentricity of the ellipse – The ratio of distances from the ellipse’s centre to its semi-major axis is known as the eccentricity of an ellipse.
  • Ellipse Formula has two foci, also known as focal points.
  • A directrix is the mathematical term for a set distance.
  • An Ellipse Formula has an eccentricity between 0 and 1. 0e1
  • Each of the distances between an ellipse’s locus and its two focal points adds up to a fixed total.
  • An Ellipse Formula has a centre and two axes, one major and one minor.

Examples on Ellipse

When a cone is cut at an angle, the result is an ellipse. The shape of the water’s surface when we tilt a glass of water is also an ellipse. Ellipse can also be seen when a hula hoop or a car tyre appears to be out of alignment.

Practice Questions on Ellipse

  1. The coordinate axes of the rectangle, which is inscribed in another ellipse that passes through the point, are aligned with the ellipse x2 + 4y2 = 4. (4, 0). Find the ellipse’s equation.


Given the elliptical equation: x2 + 4y2 = 4.

⇒ x2/4 + y2/1 = 1

Since a = 2 and b = 1,

We are aware that the ellipse’s general equation is x2/a2+ y2/b2 = 1.

(4/16) + (1/b2)= 1

⇒ b2 = 4/3

Consequently, (x2/16) plus y2/(4/3) = 1.

⇒ (x2/16) + (3y2/4) = 1

The necessary equation is x2 + 12 y2 = 16.

  1. point M is where the line connecting the extremities A and B of the main and minor axes of the ellipse x2 + 9y2 = 9 meets its auxiliary circle. Discover the triangle’s area. Its vertices are at A, M, and the origin, O.


In the given ellipse, x2 + 9y2 = 9.

⇒ (x2/9) + y2 = 1

⇒ a = 3, b = 1

A = hence (3, 0) and B = (0, 1)

The circle’s equation is x2 + y2 = 9.

The AM equation is y = (-1/3)(x + 3)

Line slope = -1/3

As a result, 3y + x – 3 = 0 and y – 1 = -1/3(x – 0)

The AM equation is 3y + x – 3 = 0.

⇒ x = -3y + 3

When we multiply x by x2 + y2, we obtain y = 9/5.

⇒ x = -12/5

So M = (-12/5, 9/5)

A = (3, 0), O = (0, 0), and M = (-12/5, 9/5) are our values.

Triangle’s area AOM is equal to (1/2)|0(0 – 9/5) + 3(9/5 – 0) – 12/5. (0-0)


= 27/10

  1. If the semi-major axis is 10 cm long and the semi-minor axis is an ellipse with a 7 cm diameter. Locate the location.


Given that a = 10 cm for an ellipse’s semi-major axis

b = 7 cm is the length of an ellipse’s semi-minor axis.

Using the formula, we can get an ellipse’s area;

Area = (x, a, b)

= π x 10 x 7

= 70 x π

Area is thus equal to 219.91 cm2.

  1. What does an ellipse’s major and minor axis mean?


Ellipses are differentiated by two axes running along the x and y axes:

Major Axis: The major axis is the ellipse’s longest diameter, running through the centre from one end to the other at the broadest part of the ellipse.

The minor axis, which passes through the centre of an ellipse at its narrowest point, has the smallest diameter. The semi-major axis makes up half of the major axis, and the semi-minor axis makes up half of the minor axis.

  1. What are the Ellipse equations?


The following is the ellipse equation with the origin as its centre and the x-axis as its main axis:

x2/a2+y2/b2 = 1

where x -a a.

The following is the ellipse equation with the main axis on the y-axis and the centre at the origin:

x2/b2+y2/a2 = 1

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FAQs (Frequently Asked Questions)

1. What are the Ellipse equations?

The following is the ellipse equation with the origin as its centre and the x-axis as its main axis:

x2/a2+y2/b2 = 1

where x -a a.

The following is the ellipse equation with the main axis on the y-axis and the centre at the origin:

x2/b2+y2/a2 = 1

2. Find the main and minor axis lengths for the equation 7x2+3y2=21.

The equation given is 7×2+3y2=21.

21 divided by both sides gives us

x2/3 + y2/7 = 1

The Ellipse Standard Equation is known.

x2/b2+y2/a2 = 1

The ellipse is centred at the origin and the main axis is on the y-axis in the equation above because the foci are on the y-axis.

then ;

B2 = 3, hence b = 1.73 as a result.

A2 = 7, which equals 2.64 for a., therefore,

Let 2a be the main axis length, which equals 5.28.

The minor axis’ length is 2b = 3.46.

3. What will the ellipse's area be?

The lengths of an ellipse’s minor and major axes define its area.

Ellipse area equals.a.b