Question

C = {x/x ∈ N, x^2 + 4 = 0}

Answer 1

Answer:

Ф= null set .

Step-by-step explanation:

x²+4=0

=> x²=-4

=> x=√-4

Given that , x is a natural number but √-4 is not natural .

c=Ф

Answer 2

x is a natural number and x

2

<40

⇒x<

40

x<6.32

So, the values of x can be 1,2,3,4,5,6

The given set in roster form is {1,2,3,4,5,6}.