Consider a binary operation *on N defined as \(a*b=a^3+b^3.\)Choose the correct answer.
Is * both associative and commutative?
Is * commutative but not associative?
Is * associative but not commutative?
Is * neither commutative nor associative?
On N, the operation * is defined as \(a*b=a^3+b^3.\)
For, a, b, ∈ N, we have: \(a*b=a^3+b^3=b^3+a^3=b*a\) [Addition is commutative in N]
Therefore, the operation * is commutative. It can be observed that:
\((1*2)*3=(1^3+2^3)*3=9*3\)= \(9^3+3^3=756\)
\(1*(2*3)=1*(2^3+3^3)=1*(8+27)=1*35=1^3+35^3=1+35^3=42876\)
∴ (1 * 2) * 3 ≠ 1 * (2 * 3) ; where 1, 2, 3 ∈ N
Therefore, the operation * is not associative.
Hence, the operation * is commutative, but not associative. Thus, the correct answer is B.
LIST I | LIST II | ||
A. | Range of y=cosec-1x | I. | R-(-1, 1) |
B. | Domain of sec-1x | II. | (0, π) |
C. | Domain of sin-1x | III. | [-1, 1] |
D. | Range of y=cot-1x | IV. | \([\frac{-π}{2},\frac{π}{2}]\)-{0} |
What is the Planning Process?
A binary operation can be understood as a function f (x, y) that applies to two elements of the same set S, such that the result will also be an element of the set S. Examples of binary operations are the addition of integers, multiplication of whole numbers, etc. A binary operation is a rule that is applied on two elements of a set and the resultant element also belongs to the same set.
Read More: Truth Table
There are four main types of binary operations which are: