Question
Mathematics Question on Functions
Let W denote the words in the English dictionary. Define the relation R by : R =\\{ (x,y), \in\, W \times \,W : the words x and y have at least one letter in commona\\} Then R is
A
reflexive, not symmetric and transitive
B
not reflexive, symmetric and transitive
C
reflexive, symmetric and not transitive
D
reflexive, symmetric and transitive
Answer
reflexive, symmetric and not transitive
Explanation
Solution
Let w∈W then (w,w)∈R∴R is reflexive. Also if w1,w2∈W and (w1,w2)∈R, then (w2,w1)∈R.∴R is symmetric. Again Let w1=INK,w2 = L I N K, w3 = L E T Then (w1,w2)∈R [∵ I, N are the common elements of w1,w2](w2,w3)∈R [∵ L is the common element of w2,w3] But (w1,w3)∈/R [∵ there is no common element of w1,,w3] ∴ R is not transitive.