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Ex 1.4, 13 (MCQ) - Chapter 1 Class 12 Relation and Functions
Last updated at August 19, 2026 by Teachoo
Whether binary commutative/associative or not
Chapter 1 Class 12 Relation and Functions
Concept wise
- Relations - Definition
- Empty and Universal Relation
- To prove relation reflexive, transitive, symmetric and equivalent
- Finding number of relations
- Function - Definition
- To prove one-one & onto (injective, surjective, bijective)
- Composite functions
- Composite functions and one-one onto
- Finding Inverse
- Inverse of function: Proof questions
- Binary Operations - Definition
-
Whether binary commutative/associative or not
- Binary operations: Identity element
- Binary operations: Inverse
Transcript
Ex 1.4, 13 Consider a binary operation * on N defined as a * b = a3 + b3. Choose the correct answer. (A) Is * both associative and commutative? (B) Is * commutative but not associative? (C) Is * associative but not commutative? (D) Is * neither commutative nor associative? Check commutative * is commutative if a * b = b * a Since a * b = b * a, ∀ a, b ∈ N * is commutative Check associative * is associative if (a * b) * c = a * (b * c) Since (a * b) * c ≠ a * (b * c), ∀ a, b, c ∈ N * is not associative Hence, B is the correct answer
