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).
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).

Solution:

The below  table which represents the octants:

(i)

    \[(1,2,3)\]

Here x, y and  z are positive.

So it lies in I octant.

(ii)

    \[(4,-2,3)\]

Here x and z are positive, y is negative

So it lies in IV octant.

(iii)

    \[(4,-2,-5)\]

Here x is positive, y and z are negative

So it lies in VIII octant.

(iv)

    \[(4,2,-5)\]

Here x and y are positive and z is negative.

So it lies in V octant.

(v)

    \[(-4,2,-5)\]

Here x and z  are negative and  y is positive

So it lies in VI octant.

(vi)

    \[(-4,2,5)\]

Here x is negative, y is positive and z is positive.

So it lies in II octant.

(vii)

    \[(-3,-1,6)\]

Here x and y are negative and z is positive.

So it lies in III octant.

(viii)

    \[(2,-4,-7)\]

Here x is positive and y and z are negative.

So it lies in VIII octant.