wikiHow Domain of a Function Calculator To find the domain of a function, you need to identify all the possible values of the input variable (usually denoted by "x") that the function can take without causing the function to break or become undefined. Here are the general steps to follow: Identify any values of x that would make the function undefined. For example, if the function includes a square root, the value inside the square root must be greater than or equal to zero. Check if there are any restrictions on the values of x based on the function's definition or context. For example, if the function represents the number of people attending a concert, x must be a non-negative integer. Write the domain using interval notation or set notation, depending on the context and the required format. For example, consider the function f(x) = 1/(x-2): x cannot be 2, since that would make the denominator 0 and the function undefined. There are no additional restrictions on the values of x based on the definition or context. Therefore, the domain of f(x) is all real numbers except 2, which can be written in interval notation as (-∞, 2) ∪ (2, ∞), or in set notation as {x | x ≠ 2}. Page