Constant equals sign is generally used when some parameter variables are constants or constant expressions, which always indicates that the relationship has nothing to do with the variables. For example, the function f(x)≡k means that no matter what the value of x is, the value of this function is always k. Generally speaking, "constant equals" will be used in two situations: ① when it needs to be emphasized; ② If "constant equals" is not used, it will cause misunderstanding. Use "equal to" in other cases.
The difference between equality and constant equality is that equality refers to under what circumstances, two numbers are equal. For example, ax=2, and when a= 1, x=2 equals. Constant x equals 2 means that x is equal to 2 in any case, which is equivalent to being either a variable or a constant. "Equal to" is generally conditional and needs to meet certain conditions before it can be established; "Constant equals" is unconditional and holds true under any circumstances.