Question

______ is a singleton.(a) A={x ∈ R : x²-x=0}(b) B = {x I x ∈ N, 2x = 3}(c) C = {x I x ∈ R : x² = -4}(d) D = {x | x ∈ Z, x is neither positive nor negative}

Answer 1

A = { x belongs to R : x^2 - x = 0}

A = { 0, 1 }

B = { x : x belongs to N, 2x = 3}

B = { }

C = { x : x belongs to R : x^2 = - 4}

C = { }

D = { x : x belongs to Z, x is neither positive nor negative}

D = { 0 }


So,

D is a singleton set.

Answer 2

A = { x belongs to R : x^2 - x = 0}

A = { 0, 1 }

B = { x : x belongs to N, 2x = 3}

B = { }

C = { x : x belongs to R : x^2 = - 4}

C = { }

D = { x : x belongs to Z, x is neither positive nor negative}

D = { 0 }

So,

D is a singleton set.