Define a symmetric relation.

Define a symmetric matrix.

Define a skew-symmetric matrix.

Define a transitive relation.

Define an reflexive relation.

Define an equivalence relation.

Define an equivalence relation and give an example.

a) what is meant by analagous organs ? b) Define variation in relation to a species why is variation beneficial to the species .

Give an example of a relation which is reflexive and symmetric but not transitive.

Give an example of a relation. Which is (i) Symmetric but neither reflexive nor transitive. (ii) Transitive but neither reflexive nor symmetric. (iii) Reflexive and symmetric but not transitive. (iv) Reflexive and transitive but not symmetric. (v) Symmetric and transitive but not reflexive.

Let A = {1,2,3}. Then number of relations containing (1,2) and (1,3) which are reflexive ans symmetric but not transitive is