NCERT Solutions
Class 11 - Mathematics - Chapter 11: INTRODUCTION TO THREE DIMENSIONAL GEOMETRY
EXERCISE 11.1

Question. 1

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

Answer:

y and z - coordinates are zero

Question. 2

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

Answer:

y - coordinate is zero

Question. 3

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)

Answer:

I, IV, VIII, V, VI, II, III, VII

Question. 4

Fill in the blanks:

(i) The x-axis and y-axis taken together determine a plane known as ______.

(ii) The coordinates of points in the XY-plane are of the form ______.

(iii) Coordinate planes divide the space into _____ octants.

Answer:

(i) XY - plane

(ii) (x, y, 0)

(iii) Eight

NCERT Solutions Class 11 – Mathematics – Chapter 11: INTRODUCTION TO THREE DIMENSIONAL GEOMETRY – EXERCISE 11.1 | Detailed Answers