\circeqThe \circeq symbol is used to denote that two quantities are approximately equal or equivalent in some context. It is often used in mathematical expressions to indicate that the values on either side of the symbol are not exactly equal, but are close enough for the purposes of the discussion or calculation.
Indicates that x is approximately equal to y.
x \circeq yShows that the function f(x) is approximately equal to g(x) for certain values of x.
f(x) \circeq g(x)Used in a context where the sum of squares of a and b is approximately equal to the square of c, possibly in an approximation of the Pythagorean theorem.
a^2 + b^2 \circeq c^2