Question

is x^2+y^2=1 a function?

Answer 1

Answer:

x2+y2=1 does not describe a function because there exist valid values of x for which more than one value of y make the equation true.

Answer 2

We recall that in function every unique value input value has an output value. One input value does not have two output values.

Given: $x^2+y^2=1$

$x^2+y^2=1$ is a circle equation whose center is origin and radius is 1 unit.

$x^2+y^2=1$ is not a function because, if we substitute values of $x$ as 1 and -1.

Then, the value of $y$ is 0.