Spot the one that does not belong

Exercise and reference answers

Questions

1. Items

   1. l
   2. λ
   3. m
   4. n

   Odd item

   λ

2. Items

   1. Skew lines
   2. Parallel lines
   3. Intersecting lines

   Odd item

   Skew lines

3. Items

   1. Direction cosines
   2. Position vector
   3. Direction ratios

   Odd item

   Position vector

4. Items

   1. l² + m² + n² = 1
   2. l = a ÷ √(a²+b²+c²)
   3. a² + b² + c² = 1

   Odd item

   a² + b² + c² = 1

Explanation