38
The three coordinate planes divide the space into ............ parts.
Explanation
Eight parts
39
If a point $P$ lies in $Y Z$-plane, then the coordinates of a point on $Y Z$-plane is of the form ........... .
Explanation
We know that, on $YZ$-plane, $x=0$. So, the coordinates of the required point is $(0, y, z)$.
40
The equation of $Y Z$-plane is ............. .
Explanation
The equation of $Y Z$-plane is $x=0$.
41
If the point $P$ lies on $Z$-axis, then coordinates of $P$ are of the form ......... .
Explanation
On the $Z$-axis, $x=0$ and $y=0$. So, the required coordinates are $(0,0, z)$.
42
The equation of $Z$-axis, are ............ .
Explanation
The equation of $Z$-axis, $x=0$ and $y=0$.