Number System

Exercise 1

1. Using appropriate properties find

2. Write the additive inverse of following:

3. Verify that –(-x) = x for

4. Find the multiplicative inverse of the following:

(vi) -1

Answer: 1

5. Name the property under multiplication used in each of the following:

Answer: Here, 1 is the multiplicative identity.

Answer: Here commutativity of multiplication is shown.

Answer: Here, multiplicative inverse is used.

Answer: Here, associativity is being used.

Hence, this is not a case of multiplicative inverse.

Hence, this is a case of multiplicative inverse.

10. Write.

(i) The rational number that does not have a reciprocal.

Answer: 0 does not have a reciprocal. Because a number divided by 0 is undefined.

(ii) The rational numbers that are equal to their reciprocals.

Answer: 1 and -1 are equal to their reciprocals.

(iii) The rational number that is equal to its negative.

Answer: 0 is the number equal to its negative.