Respuesta :

Answer:

Step-by-step explanation:

x 2 + y 2 = 9

is not a function

Explanation:

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 + y 2= 9 XXXX

if (for example)  

x = 0 XXXX

there are two values for  

y  (namely  + 3  and  − 3 ) which satisfy the equation

and therefore the equation is not a function.

So general equation of circle

  • (x-h)²+(y-k)²=r²

(h,k) is centre and r is radius

here radius is

  • 2.828units
  • Centre is origin

So equation

  • (x-0)²+(y-0)²=(2.828)²
  • x²+y²=8