Thinking about the graph of y, the rate of change is zero whenever there is an extremum.
First, differentiate y.

Next, find the zeros of y' by factoring.

Now, we substitute these x-values into the
original equation to find the coordinates.
Answer:
x²+y²=16
Step-by-step explanation:
the general equation for a circle is given as :
(x−h)²+(y−k)²=r²
where (h, k) is the coordinate of the center of the circle and r is the radius
in this case h=0, k=0 and r = 4
equation becomes
x²+y²=4²
or
x²+y²=16
Answer:
A value, or values, we can put in place of a variable (such as x) that makes the equation true.
Example: x + 2 = 7
When we put 5 in place of x we get: 5 + 2 = 7
5 + 2 = 7 is true, so x = 5 is a solution
Probably true
you can test it too