Section 1
Introduction
A point is on the $x$ -axis. What are its $y$ -coordinate and $z$ -coordinates?
A point is in the XZ-plane. What can you say about its $y$ -coordinate?
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)$
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.