Question

Is x ^ 2 + y ^ 2 = 6 a function?

Answer 1

not a function

Explanation:

for example

In order for an equation to represent a function any single value of x must have at most one corresponding value of y which satisfies the equation.

For x2+y2=9

XXXXif (for example) x=0

XXXXthere are two values for y (namely +3 and −3) which satisfy the equation

and therefore the equation is not a function.