Question 3 of 13beginner🔧 ApplyShort Answer2 marks

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)(1,2,3), (4,-2,3), (4,-2,-5), (4,2,-5), (-4,2,-5), (-4,2,5), (-3,-1,6) (-2,-4,-7).

Correct Answer

To determine the octant, we observe the signs of the x,y,x, y, and zz coordinates for each point. The point (1,2,3)(1,2,3) has signs (+,+,+)(+,+,+), so it lies in Octant I. The point (4,−2,3)(4,-2,3) has signs (+,−,+)(+,-,+), placing it in Octant IV. The point (4,−2,−5)(4,-2,-5) has signs (+,−,−)(+,-,-), so it lies in Octant VIII.

The point (4,2,−5)(4,2,-5) has signs (+,+,−)(+,+,-), placing it in Octant V. The point (−4,2,−5)(-4,2,-5) has signs (−,+,−)(-,+,-), so it lies in Octant VI. The point (−4,2,5)(-4,2,5) has signs (−,+,+)(-,+,+), placing it in Octant II.

Finally, the point (−3,−1,6)(-3,-1,6) has signs (−,−,+)(-,-,+), so it lies in Octant III. The point (−2,−4,−7)(-2,-4,-7) has signs (−,−,−)(-,-,-), placing it in Octant VII.

Exercise: EXERCISE 11.1 | Q: 3 | (Page Page 4)
For More Understanding

Explanation

The answer is derived from the sign convention table provided in the context. The table maps the signs of the x, y, and z coordinates to specific octants: I (+,+,+)(+,+,+), II (−,+,+)(-,+,+), III (−,−,+)(-,-,+), IV (+,−,+)(+,-,+), V (+,+,−)(+,+,-), VI (−,+,−)(-,+,-), VII (−,−,−)(-,-,-), and VIII (+,−,−)(+,-,-). By comparing the sign of each coordinate for every point with this table, the correct octant is identified.

Solution Steps

  1. Step 1: Identify the signs of the coordinates (x,y,z)(x, y, z) for each given point.

  2. Step 2: Match the identified signs with the octant sign table (e.g., (+,+,+)(+,+,+) corresponds to Octant I, (−,−,−)(-,-,-) corresponds to Octant VII).

  3. Step 3: List the corresponding octant for each point based on the sign match.