CBSE (Commerce) Class 11CBSE
Share

NCERT solutions for Class 11 Mathematics chapter 12 - Introduction to Three Dimensional Geometry

Mathematics Textbook for Class 11

NCERT Mathematics Class 11 Chapter 12: Introduction to Three Dimensional Geometry

Chapter 12: Introduction to Three Dimensional Geometry solutions [Page 271]

Q 1 | Page 271

A point is on the x-axis. What are its y-coordinates and z-coordinates?

Q 2 | Page 271

A point is in the XZ-plane. What can you say about its y-coordinate?

Q 3 | Page 271

Name the octants in which the following points lie:

(1, 2, 3), (4, –2, 3), (4, –2, –5), (4, 2, –5), (–4, 2, –5), (–4, 2, 5),

(–3, –1, 6), (2, –4, –7)

Q 4.1 | Page 271

Fill in the blanks:

The x-axis and y-axis taken together determine a plane known as_______.

Q 4.2 | Page 271

Fill in the blanks:

The coordinates of points in the XY-plane are of the form _______.

Q 4.3 | Page 271

Fill in the blanks:

Coordinate planes divide the space into ______ octants.

Chapter 12: Introduction to Three Dimensional Geometry solutions [Page 273]

Q 1.1 | Page 273

Find the distance between the pairs of points

(2, 3, 5) and (4, 3, 1)

Q 1.2 | Page 273

Find the distance between the pairs of points:

(–3, 7, 2) and (2, 4, –1)

Q 1.3 | Page 273

Find the distance between the pairs of points:

(–1, 3, –4) and (1, –3, 4)

Q 1.4 | Page 273

Find the distance between the following pairs of points:

(2, –1, 3) and (–2, 1, 3)

Q 2 | Page 273

Show that the points (–2, 3, 5), (1, 2, 3) and (7, 0, –1) are collinear.

Q 3.1 | Page 273

Verify the following: (0, 7, –10), (1, 6, –6) and (4, 9, –6) are the vertices of an isosceles triangle.

Q 3.2 | Page 273

Verify the following: (0, 7, 10), (–1, 6, 6) and (–4, 9, 6) are the vertices of a right angled triangle.

Q 3.3 | Page 273

Verify the following: (–1, 2, 1), (1, –2, 5), (4, –7, 8) and (2, –3, 4) are the vertices of a parallelogram.

Q 4 | Page 273

Find the equation of the set of points which are equidistant from the points (1, 2, 3) and (3, 2, –1).

Q 5 | Page 273

Find the equation of the set of points P, the sum of whose distances from A (4, 0, 0) and B (–4, 0, 0) is equal to 10.

Chapter 12: Introduction to Three Dimensional Geometry solutions [Page 277]

Q 1 | Page 277

Find the coordinates of the point which divides the line segment joining the points (–2, 3, 5) and (1, –4, 6) in the ratio (i) 2:3 internally, (ii) 2:3 externally.

Q 2 | Page 277

Given that P (3, 2, –4), Q (5, 4, –6) and R (9, 8, –10) are collinear. Find the ratio in which Q divides PR.

Q 3 | Page 277

Find the ratio in which the YZ-plane divides the line segment formed by joining the points (–2, 4, 7) and (3, –5, 8).

Q 4 | Page 277

Using section formula, show that the points A (2, –3, 4), B (–1, 2, 1) and C(0, 1/3 , 2) are collinear.

Q 5 | Page 277

Find the coordinates of the points which trisect the line segment joining the points P (4, 2, –6) and Q (10, –16, 6).

Chapter 12: Introduction to Three Dimensional Geometry solutions [Pages 278 - 279]

Q 1 | Page 278

Three vertices of a parallelogram ABCD are A (3, –1, 2), B (1, 2, –4) andC (–1, 1, 2). Find the coordinates of the fourth vertex.

Q 2 | Page 278

Find the lengths of the medians of the triangle with vertices A (0, 0, 6), B (0, 4, 0) and (6, 0, 0).

Q 3 | Page 278

If the origin is the centroid of the triangle PQR with vertices P (2a, 2, 6), Q (–4, 3b, –10) and R (8, 14, 2c), then find the values of ab and c

Q 4 | Page 279

Find the coordinates of a point on y-axis which are at a distance of 5sqrt2 from the point P (3, –2, 5).

Q 5 | Page 279

A point R with x-coordinate 4 lies on the line segment joining the pointsP (2, –3, 4) and Q (8, 0, 10). Find the coordinates of the point R.

[Hint suppose R divides PQ in the ratio k: 1. The coordinates of the point R are given by ((8k + 2)/(k+1), (-3)/(k+1), (10k + 4)/(k+1))

Q 6 | Page 279

If A and B be the points (3, 4, 5) and (–1, 3, –7), respectively, find the equation of the set of points P such that PA2 + PB2 = k2, where k is a constant.

Chapter 12: Introduction to Three Dimensional Geometry

NCERT Mathematics Class 11 NCERT solutions for Class 11 Mathematics chapter 12 - Introduction to Three Dimensional Geometry

NCERT solutions for Class 11 Maths chapter 12 (Introduction to Three Dimensional Geometry) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the CBSE Mathematics Textbook for Class 11 solutions in a manner that help students grasp basic concepts better and faster.

Further, we at Shaalaa.com are providing such solutions so that students can prepare for written exams. NCERT textbook solutions can be a core help for self-study and acts as a perfect self-help guidance for students.

Concepts covered in Class 11 Mathematics chapter 12 Introduction to Three Dimensional Geometry are Coordinate Axes and Coordinate planes, Coordinates of a Point in Space, Distance Between Two Points, Section Formula, Three Dimessional Space.

Using NCERT Class 11 solutions Introduction to Three Dimensional Geometry exercise by students are an easy way to prepare for the exams, as they involve solutions arranged chapter-wise also page wise. The questions involved in NCERT Solutions are important questions that can be asked in the final exam. Maximum students of CBSE Class 11 prefer NCERT Textbook Solutions to score more in exam.

Get the free view of chapter 12 Introduction to Three Dimensional Geometry Class 11 extra questions for Maths and can use Shaalaa.com to keep it handy for your exam preparation

S