Solve (x^2) <= 1- (y^2)?

Answer 1

This is just the inside of the unit circle including its circumference.
The unit circle (circle at the origin with radius=1) is
x^2 + y^2 = 1
And you want x^2 + y^2 ≤ 1
so its the circle plus its inside.
( if it had been x^2 + y^2 ≥ 1 it would be the circle plus everything outside )
If you wanted x in terms of y, you just get |x| ≤ √(1-y^2) .

Answer 2

It belongs to the area inside and outline of a circle
with radius equal to 1. The Center of the Circle is
the Coordinate => (x, y) = (0, 0)

EXAMPLE:
If it would be instead of
"less than or equal to",
"less than" only.
I would be the area inside the circunference and
not including the circunference outline.

SOMETHING TO KNOW:
circunference is the outline.
circle is the area.

FURTHER INFO:
Also, since x*x + y*y = 1
it is quite useful to understand the trigonometric
relationships like:

x = cos@
y = sin@

Answer 3

x^2+y^2=1
x<=+/-1,y<=+/-1