Question

The signs of the X, Y and Z coordinates of a point that lies in the octant OXYZ' is

• A. ( + , - , -)
• B. (-, - , +)
• C. (- , + , +)
• D. ( + , + , -)

Answer 1

The correct option is D

( + , + , -)

Each coordinate of the point P takes the positive or negative sign depending on whether L, M, N lies on the positive or negative X, Y and Z axis.
Following this rule , the signs of the triplet of coordinates in the 8 octants will be :
OXYZ(+, +, +), OX'YZ (- , + , +), OX'Y'Z( - , - , +) OXY'Z (+ , - , +), OXYZ'( +, +, -) , OX'YZ'( -, + , - ), OX'Y'Z'( - , - , -), OXY'Z'( + , - , -) ,