COMEDK2019MathematicsMathematical Reasoning
Which of the following is false?
Options
- AAddition is commutative in N .
- BMultiplication is associative in N .
- CIf a * b=a^ b for all a, b N , then * is commutative in N .
- DAddition is associative in N .
Correct answer
C. If a * b=a^ b for all a, b N , then * is commutative in N .
Step-by-step solution
a*b=a^ b and b * a=b^ a a * b b a ; a, b N So, addition is commutative in N . (b) (a b) c=a (b c), a, b, c N . So, multiplication is associative in N . (c) a*b=a^ b and b: a=b^ a a * b b a ; a, b N So, * is commutative in N is false. (d) (a+b)+c=a+(b+c), a, b and c N . So, addition is associative in N .