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 $y=0$.
43
A line is parallel to $X Y$-plane if all the points on the line have equal ........... .
Explanation
$z$-coordinates.
44
A line is parallel to $X$-axis, if all the points on the line have equal .............. .
Explanation
$y$ and $z$-coordinates.