Question

The equation for a circle is shown x ^ 2 + y ^ 2 = 9 Which statement best explains why the equation does not describe a function?

Answer 1

x2+y2=9 is not a function

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

x

2

+

y

2

=

9

XXXX

if (for example)

x=0XXXX there are two values for y (namely +3 and −3) which satisfy the equation