Exercise 1.8 (1)

1. Write negation of each of the following statements.

i) All the stars are shining if it is night.
Ans: Some stars are shining and it is night.

ii) ∀ n ∈ N, n + 1 > 0
Ans: ∃ n ∈N such that n+1 ≤0.

iii) ∃ n ∈ N, (n2 + 2) is odd number
Ans: ∀ n ∈N, (n^2+2) is not odd number.

iv) Some continuous functions are differentiable.
Ans: All continuous functions are not differentiable.