How to limit the position of an object within a circle?

I was trying to use some mathematical formulas, but is giving error.

(posx ²) + (posy ²) = (radius²)

where,

maximum position of posx ² should be (radius ²) - (posy ²)

and

maximum position posy ² should be (radius ²) - (posx ²)

I am using Float Limit in X and Y position, with Float Script in each.

for example,

R = 50

If the value of x is equal to 15, the maximum value of y can only be 35.

If the value of y is equal to 25, the maximum value of x can only be 25.

ERROR: Circular Dependency