What is the formula to graph a circle in a graphic calculator?

Question

Using a graphic calculator what is the input for "y=" to graph a circle?

Answer 1

well using the y = function, you may need to create a positive and negative graph

for a circle with a center of 0, 0:

square root ( x^2 - r^2) (replace r with your desired radius)
and
- square root( x^2 - r^2)

Answer 2

y=±sqrt(100-x^2) is what I always use to graph a circle with radius 10. And before doing that, set viewing window to "square", so the x's and y's are the same size.

Answer 3

(x - h)^2 + (y - k)^2 = r^2
(y - k)^2 = -(x - h)^2 + r^2
y - k = sqrt(-(x - h)^2 + r^2)
y = sqrt(-(x - h)^2 + r^2) + k
or
y = sqrt(r^2 - (x - h)^2) + k

whereas (h,k) is the center of the circle and "r" is the radius or half the distance from one endpoint to the other.

Answer 4

y1 = sqrt(x^2 + #^2)
y2= -sqrt(x^2 + #^2)

You can also change the MODE to POLar and graph r = # (r is the radius)