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NCERT Exemplar solutions for Mathematics [English] Class 11 chapter 11 - Conic Sections [Latest edition]

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NCERT Exemplar solutions for Mathematics [English] Class 11 chapter 11 - Conic Sections - Shaalaa.com
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Solutions for Chapter 11: Conic Sections

Below listed, you can find solutions for Chapter 11 of CBSE NCERT Exemplar for Mathematics [English] Class 11.


Solved ExamplesExercise
Solved Examples [Pages 193 - 201]

NCERT Exemplar solutions for Mathematics [English] Class 11 11 Conic Sections Solved Examples [Pages 193 - 201]

Short Answer

Solved Examples | Q 1 | Page 193

Find the centre and radius of the circle x2 + y2 – 2x + 4y = 8

Solved Examples | Q 2 | Page 193

If the equation of the parabola is x2 = – 8y, find coordinates of the focus, the equation of the directrix and length of latus rectum.

Solved Examples | Q 3 | Page 194

Given the ellipse with equation 9x2 + 25y2 = 225, find the major and minor axes, eccentricity, foci and vertices.

Solved Examples | Q 4 | Page 194

Find the equation of the ellipse with foci at (± 5, 0) and x = `36/5` as one of the directrices.

Solved Examples | Q 5 | Page 194

For the hyperbola 9x2 – 16y2 = 144, find the vertices, foci and eccentricity

Solved Examples | Q 6 | Page 194

Find the equation of the hyperbola with vertices at (0, ± 6) and e = `5/3`. Find its foci.

Long Answer

Solved Examples | Q 7 | Page 195

Find the equation of the circle which passes through the points (20, 3), (19, 8) and (2, –9). Find its centre and radius.

Solved Examples | Q 8 | Page 195

An equilateral triangle is inscribed in the parabola y2 = 4ax whose one vertex is at the vertex of the parabola. Find the length of the side of the triangle.

Solved Examples | Q 9 | Page 196

Find the equation of the ellipse which passes through the point (–3, 1) and has eccentricity `sqrt(2)/5`, with x-axis as its major axis and centre at the origin.

Solved Examples | Q 10 | Page 196

Find the equation of the hyperbola whose vertices are (± 6, 0) and one of the directrices is x = 4.

Objective Type Questions from 11 to 16

Solved Examples | Q 11 | Page 197

The equation of the circle in the first quadrant touching each coordinate axis at a distance of one unit from the origin is ______.

  • x2 + y2 – 2x – 2y + 1 = 0

  • x2 + y2 – 2x – 2y – 1 = 0

  • x2 + y2 – 2x – 2y = 0

  • x2 + y2 – 2x + 2y – 1 = 0

Solved Examples | Q 12 | Page 197

The equation of the circle having centre (1, –2) and passing through the point of intersection of the lines 3x + y = 14 and 2x + 5y = 18 is ______.

  • x2 + y2 – 2x + 4y – 20 = 0

  • x2 + y2 – 2x – 4y – 20 = 0

  • x2 + y2 + 2x – 4y – 20 = 0

  • x2 + y2 + 2x + 4y – 20 = 0

Solved Examples | Q 13 | Page 197

The area of the triangle formed by the lines joining the vertex of the parabola x2 = 12y to the ends of its latus rectum is ______.

  • 12 sq.units

  • 16 sq.units

  • 18 sq.units

  • 24 sq.units

Solved Examples | Q 14 | Page 198

The equations of the lines joining the vertex of the parabola y2 = 6x to the points on it which have abscissa 24 are ______.

  • y ± 2x = 0

  • 2y ± x = 0

  • x ± 2y = 0

  • 2x ± y = 0

Solved Examples | Q 15 | Page 198

The equation of the ellipse whose centre is at the origin and the x-axis, the major axis, which passes through the points (–3, 1) and (2, –2) is ______.

  • 5x2 + 3y2 = 32

  • 3x2 + 5y2 = 32

  • 5x2 – 3y2 = 32

  • 3x2 + 5y2 + 32 = 0

Solved Examples | Q 16 | Page 198

The length of the transverse axis along x-axis with centre at origin of a hyperbola is 7 and it passes through the point (5, –2). The equation of the hyperbola is ______.

  • `4/49 x^2 - 196/51 y^2` = 1

  • `49/4 x^2 - 51/196 y^2` = 1

  • `4/49 x^2 - 51/196 y^2` = 1

  • None of these

State whether the following statement is True or False: 17 and 18

Solved Examples | Q 17 | Page 199

Circle on which the coordinates of any point are (2 + 4 cosθ, –1 + 4 sinθ) where θ is parameter is given by (x – 2)2 + (y + 1)2 = 16.

  • True

  • False

Solved Examples | Q 18 | Page 199

A bar of given length moves with its extremities on two fixed straight lines at right angles. Any point of the bar describes an ellipse.

  • True

  • False

Fill in the blanks 19 to 23

Solved Examples | Q 19 | Page 200

The equation of the circle which passes through the point (4, 5) and has its centre at (2, 2) is ______.

Solved Examples | Q 20 | Page 200

A circle has radius 3 units and its centre lies on the line y = x – 1. If it passes through the point (7, 3), its equation is ______.

Solved Examples | Q 21 | Page 200

If the latus rectum of an ellipse with axis along x-axis and centre at origin is 10, distance between foci = length of minor axis, then the equation of the ellipse is ______.

Solved Examples | Q 22 | Page 201

The equation of the parabola whose focus is the point (2, 3) and directrix is the line x – 4y + 3 = 0 is ______.

Solved Examples | Q 23 | Page 201

The eccentricity of the hyperbola `x^2/a^2 - y^2/b^2` = 1 which passes through the points (3, 0) and `(3 sqrt(2), 2)` is ______.

Exercise [Pages 202 - 207]

NCERT Exemplar solutions for Mathematics [English] Class 11 11 Conic Sections Exercise [Pages 202 - 207]

Short Answer

Exercise | Q 1 | Page 202

Find the equation of the circle which touches the both axes in first quadrant and whose radius is a.

Exercise | Q 2 | Page 202

Show that the point (x, y) given by x = `(2at)/(1 + t^2)` and y = `(a(1 - t^2))/(1 - t^2)` lies on a circle for all real values of t such that –1 < t < 1 where a is any given real numbers.

Exercise | Q 3 | Page 202

If a circle passes through the point (0, 0) (a, 0), (0, b) then find the coordinates of its centre.

Exercise | Q 4 | Page 202

Find the equation of the circle which touches x-axis and whose centre is (1, 2).

Exercise | Q 5 | Page 202

If the lines 3x – 4y + 4 = 0 and 6x – 8y – 7 = 0 are tangents to a circle, then find the radius of the circle.

Exercise | Q 6 | Page 202

Find the equation of a circle which touches both the axes and the line 3x – 4y + 8 = 0 and lies in the third quadrant.

Exercise | Q 7 | Page 202

If one end of a diameter of the circle x2 + y2 – 4x – 6y + 11 = 0 is (3, 4), then find the coordinate of the other end of the diameter

Exercise | Q 8 | Page 202

Find the equation of the circle having (1, –2) as its centre and passing through 3x + y = 14, 2x + 5y = 18

Exercise | Q 9 | Page 202

If the line y = `sqrt(3)x + k` touches the circle x2 + y2 = 16, then find the value of k.

Exercise | Q 10 | Page 202

Find the equation of a circle concentric with the circle x2 + y2 – 6x + 12y + 15 = 0 and has double of its area.

Exercise | Q 11 | Page 202

If the latus rectum of an ellipse is equal to half of minor axis, then find its eccentricity.

Exercise | Q 12 | Page 202

Given the ellipse with equation 9x2 + 25y2 = 225, find the eccentricity and foci.

Exercise | Q 13 | Page 202

If the eccentricity of an ellipse is `5/8` and the distance between its foci is 10, then find latus rectum of the ellipse.

Exercise | Q 14 | Page 203

Find the equation of ellipse whose eccentricity is `2/3`, latus rectum is 5 and the centre is (0, 0).

Exercise | Q 15 | Page 203

Find the distance between the directrices of the ellipse `x^2/36 + y^2/20` = 1

Exercise | Q 16 | Page 203

Find the coordinates of a point on the parabola y2 = 8x whose focal distance is 4.

Exercise | Q 17 | Page 203

Find the length of the line segment joining the vertex of the parabola y2 = 4ax and a point on the parabola where the line segment makes an angle θ to the x-axis.

Exercise | Q 18 | Page 203

If the points (0, 4) and (0, 2) are respectively the vertex and focus of a parabola, then find the equation of the parabola.

Exercise | Q 19 | Page 203

If the line y = mx + 1 is tangent to the parabola y2 = 4x then find the value of m.

Exercise | Q 20 | Page 203

If the distance between the foci of a hyperbola is 16 and its eccentricity is `sqrt(2)`, then obtain the equation of the hyperbola.

Exercise | Q 21 | Page 203

Find the eccentricity of the hyperbola 9y2 – 4x2 = 36.

Exercise | Q 22 | Page 203

Find the equation of the hyperbola with eccentricity `3/2` and foci at (± 2, 0).

Long Answer

Exercise | Q 23 | Page 203

If the lines 2x – 3y = 5 and 3x – 4y = 7 are the diameters of a circle of area 154 square units, then obtain the equation of the circle.

Exercise | Q 24 | Page 203

Find the equation of the circle which passes through the points (2, 3) and (4, 5) and the centre lies on the straight line y – 4x + 3 = 0.

Exercise | Q 25 | Page 203

Find the equation of a circle whose centre is (3, –1) and which cuts off a chord of length 6 units on the line 2x – 5y + 18 = 0.

Exercise | Q 26 | Page 203

Find the equation of a circle of radius 5 which is touching another circle x2 + y2 – 2x – 4y – 20 = 0 at (5, 5).

Exercise | Q 27 | Page 203

Find the equation of a circle passing through the point (7, 3) having radius 3 units and whose centre lies on the line y = x – 1.

Exercise | Q 28.(a) | Page 203

Find the equation of the following parabolas:

Directrix x = 0, focus at (6, 0)

Exercise | Q 28.(b) | Page 203

Find the equation of the following parabolas:

Vertex at (0, 4), focus at (0, 2)

Exercise | Q 28.(c) | Page 203

Find the equation of the following parabolas:

Focus at (–1, –2), directrix x – 2y + 3 = 0

Exercise | Q 29 | Page 204

Find the equation of the set of all points the sum of whose distances from the points (3, 0) and (9, 0) is 12.

Exercise | Q 30 | Page 204

Find the equation of the set of all points whose distance from (0, 4) are `2/3` of their distance from the line y = 9.

Exercise | Q 31 | Page 204

Show that the set of all points such that the difference of their distances from (4, 0) and (– 4, 0) is always equal to 2 represent a hyperbola.

Exercise | Q 32.(a) | Page 204

Find the equation of the hyperbola with vertices (± 5, 0), foci (± 7, 0)

Exercise | Q 32.(b) | Page 204

Find the equation of the hyperbola with vertices (0, ± 7), e = `4/3`

Exercise | Q 32.(c) | Page 204

Find the equation of the hyperbola with foci `(0, +- sqrt(10))`, passing through (2, 3)

State whether the following statement is True or False: 33 to 40

Exercise | Q 33 | Page 204

The line x + 3y = 0 is a diameter of the circle x2 + y2 + 6x + 2y = 0.

  • True

  • False

Exercise | Q 34 | Page 204

The shortest distance from the point (2, –7) to the circle x2 + y2 – 14x – 10y – 151 = 0 is equal to 5.

  • True

  • False

Exercise | Q 35 | Page 204

If the line lx + my = 1 is a tangent to the circle x2 + y2 = a2, then the point (l, m) lies on a circle.

  • True

  • False

Exercise | Q 36 | Page 204

The point (1, 2) lies inside the circle x2 + y2 – 2x + 6y + 1 = 0.

  • True

  • False

Exercise | Q 37 | Page 204

The line lx + my + n = 0 will touch the parabola y2 = 4ax if ln = am2.

  • True

  • False

Exercise | Q 38 | Page 204

If P is a point on the ellipse `x^2/16 + y^2/25` = 1 whose foci are S and S′, then PS + PS′ = 8.

  • True

  • False

Exercise | Q 39 | Page 204

The line 2x + 3y = 12 touches the ellipse `x^2/9 + y^2/4` = 2 at the point (3, 2).

  • True

  • False

Exercise | Q 40 | Page 204

The locus of the point of intersection of lines `sqrt(3)x - y - 4sqrt(3)k` = 0 and `sqrt(3)kx + ky - 4sqrt(3)` = 0 for different value of k is a hyperbola whose eccentricity is 2.

  • True

  • False

Fill in the Blank 41 to 46

Exercise | Q 41 | Page 205

The equation of the circle having centre at (3, – 4) and touching the line 5x + 12y – 12 = 0 is ______.

Exercise | Q 42 | Page 205

The equation of the circle circumscribing the triangle whose sides are the lines y = x + 2, 3y = 4x, 2y = 3x is ______.

Exercise | Q 43 | Page 205

An ellipse is described by using an endless string which is passed over two pins. If the axes are 6 cm and 4 cm, the length of the string and distance between the pins are ______.

Exercise | Q 44 | Page 205

The equation of the ellipse having foci (0, 1), (0, –1) and minor axis of length 1 is ______. 

Exercise | Q 45 | Page 205

The equation of the parabola having focus at (–1, –2) and the directrix x – 2y + 3 = 0 is ______.

Exercise | Q 46 | Page 205

The equation of the hyperbola with vertices at (0, ± 6) and eccentricity `5/3` is ______ and its foci are ______.

Objective Type Questions from 47 to 59

Exercise | Q 47 | Page 205

The area of the circle centred at (1, 2) and passing through (4, 6) is ______.

  • 10π

  • 25π

  • None of these

Exercise | Q 48 | Page 205

Equation of a circle which passes through (3, 6) and touches the axes is ______.

  • x2 + y2 + 6x + 6y + 3 = 0

  • x2 + y2 – 6x – 6y – 9 = 0

  • x2 + y2 – 6x – 6y + 9 = 0

  • None of these

Exercise | Q 49 | Page 205

Equation of the circle with centre on the y-axis and passing through the origin and the point (2, 3) is ______.

  • x2 + y2 + 13y = 0

  • 3x2 + 3y2 + 13x + 3 = 0

  • 6x2 + 6y2 – 13x = 0

  • x2 + y2 + 13x + 3 = 0

Exercise | Q 50 | Page 206

The equation of a circle with origin as centre and passing through the vertices of an equilateral triangle whose median is of length 3a is ______.

  • x2 + y2 = 9a2

  • x2 + y2 = 16a2

  • x2 + y2 = 4a2

  • x2 + y2 = a2

Exercise | Q 51 | Page 206

If the focus of a parabola is (0, –3) and its directrix is y = 3, then its equation is ______.

  • x2 = –12y

  • x2 = 12y

  • y2 = –12x

  • y2 = 12x

Exercise | Q 52 | Page 206

If the parabola y2 = 4ax passes through the point (3, 2), then the length of its latus rectum is ______.

  • `2/3`

  • `4/3`

  • `1/3`

  • 4

Exercise | Q 53 | Page 206

If the vertex of the parabola is the point (–3, 0) and the directrix is the line x + 5 = 0, then its equation is ______.

  • y2 = 8(x + 3)

  • x2 = 8(y + 3)

  • y2 = – 8(x + 3)

  • y2 = 8(x + 5)

Exercise | Q 54 | Page 206

The equation of the ellipse whose focus is (1, –1), the directrix the line x – y – 3 = 0 and eccentricity `1/2` is ______.

  • 7x2 + 2xy + 7y2 – 10x + 10y + 7 = 0

  • 7x2 + 2xy + 7y2 – 10x + 10y + 7 = 0

  • 7x2 + 2xy + 7y2 + 10x – 10y – 7 = 0

  • None

Exercise | Q 55 | Page 206

The length of the latus rectum of the ellipse 3x2 + y2 = 12 is ______.

  • 4

  • 3

  • 8

  • `4/sqrt(3)`

Exercise | Q 56 | Page 206

If e is the eccentricity of the ellipse `x^2/a^2 + y^2/b^2` = 1 (a < b), then ______.

  • b2 = a2(1 – e2)

  • a2 = b2(1 – e2)

  • a2 = b2(e2 – 1)

  • b2 = a2(e2 – 1)

Exercise | Q 57 | Page 207

The eccentricity of the hyperbola whose latus rectum is 8 and conjugate axis is equal to half of the distance between the foci is ______.

  • `4/3`

  • `4/sqrt(3)`

  • `2/sqrt(3)`

  • None of these

Exercise | Q 58 | Page 207

The distance between the foci of a hyperbola is 16 and its eccentricity is `sqrt(2)`. Its equation is ______.

  • x2 – y2 = 32

  • `x^2/4 - y^2/9` = 1

  • 2x2 – 3y2 = 7

  • None of these

Exercise | Q 59 | Page 207

Equation of the hyperbola with eccentricty `3/2` and foci at (± 2, 0) is ______.

  • `x^2/4 - y^2/5 = 4/9`

  • `x^2/9 - y^2/9 = 4/9`

  • `x^2/4 - y^2/9` = 1

  • None of these

Solutions for 11: Conic Sections

Solved ExamplesExercise
NCERT Exemplar solutions for Mathematics [English] Class 11 chapter 11 - Conic Sections - Shaalaa.com

NCERT Exemplar solutions for Mathematics [English] Class 11 chapter 11 - Conic Sections

Shaalaa.com has the CBSE Mathematics Mathematics [English] Class 11 CBSE solutions in a manner that help students grasp basic concepts better and faster. The detailed, step-by-step solutions will help you understand the concepts better and clarify any confusion. NCERT Exemplar solutions for Mathematics Mathematics [English] Class 11 CBSE 11 (Conic Sections) include all questions with answers and detailed explanations. This will clear students' doubts about questions and improve their application skills while preparing for board exams.

Further, we at Shaalaa.com provide such solutions so students can prepare for written exams. NCERT Exemplar textbook solutions can be a core help for self-study and provide excellent self-help guidance for students.

Concepts covered in Mathematics [English] Class 11 chapter 11 Conic Sections are Sections of a Cone, Introduction of Parabola, Standard Equations of Parabola, Latus Rectum, Introduction of Ellipse, Relationship Between Semi-major Axis, Semi-minor Axis and the Distance of the Focus from the Centre of the Ellipse, Special Cases of an Ellipse, Concept of Circle, Standard Equations of an Ellipse, Latus Rectum, Introduction of Hyperbola, Eccentricity, Standard Equation of Hyperbola, Latus Rectum, Standard Equation of a Circle, Eccentricity.

Using NCERT Exemplar Mathematics [English] Class 11 solutions Conic Sections exercise by students is an easy way to prepare for the exams, as they involve solutions arranged chapter-wise and also page-wise. The questions involved in NCERT Exemplar Solutions are essential questions that can be asked in the final exam. Maximum CBSE Mathematics [English] Class 11 students prefer NCERT Exemplar Textbook Solutions to score more in exams.

Get the free view of Chapter 11, Conic Sections Mathematics [English] Class 11 additional questions for Mathematics Mathematics [English] Class 11 CBSE, and you can use Shaalaa.com to keep it handy for your exam preparation.

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