and how does it relate to circle coordinate geometry?
please explain in detail, thanks
Consider the equation. first we find the points of intersection with the axes. For x axis y = 0. Put y=o and we get x = +4 or -4. so the curve intersects x axis at ( 4,0) and (-4,0). Now for y axis put x = 0 and we get y = +4 or -4 and the points of intersection would be ( 0,4) and (0,-4). We can see that as the value of x increases from 0 to 4 the value of x keeps decreasing by similar interpretation we conclude that it is the equation of a circle with center (0,0) and radius = 4.
We can also find the intervals where the function would be increasing or decreasing and we will come to the same conclusion that it is the equation of a circle.