Question

For what value of x the relation S: {(x2+3,4), (5,2)} is not a function?

Answer 1

x = sqrt(2), -sqrt(2)

Explanation:

For a function, there cannot be multiple outputs for the same input, therefore x²+3 should not be 5

x² + 3 = 5

x² = 2

x = +/- sqrt(2)

Answer 2

x = ±sqrt(2)

Explanation:

It is not a function if the same input goes to 2 different outputs

x^2 +3 =5 would cause the same input to go to 2 different outputs

Subtract 3 from each side

x^2 +3-3 =5-3

x^2 = 2

Take the square root of each side

sqrt(x^2) = ±sqrt(2)

x = ±sqrt(2)