Question

Which one of the following is not a function? 

A. {(x, y) : x, y ∈ R, x² = y} 

B. {(x, y) : x, y ∈ R, y² = x} 

C. {(x, y) : x, y ∈ R, x = y³} 

D. {(x, y) : x, y ∈ R, y = x³}

Answer 1

Option : (B)

A function is said to exist when we get a unique value for any value of x.. 

Therefore, 

Option B is correct.. y² = x is not a function as for each value of x, we will get 2 values of y.. which is not as per the definition of a function..