1. In Mathematics:
* Undefined expression: An expression in mathematics that has no defined value. This often occurs when dividing by zero, taking the square root of a negative number, or applying certain operations to infinity.
* Undefined function: A function that doesn't have a defined value for certain inputs. For example, the function f(x) = 1/x is undefined at x = 0.
2. In Programming:
* Undefined variable: A variable that has been declared but not yet assigned a value. Accessing an undefined variable usually results in an error.
* Undefined function: A function that doesn't exist or hasn't been declared. Calling an undefined function will likely cause an error.
3. In General Usage:
* Not defined: Something that lacks a clear definition, description, or meaning. It can also mean "not established" or "not determined."
Example:
* "The answer to 1/0 is undefined." (Mathematics)
* "The variable 'myAge' is undefined." (Programming)
* "The rules of the game are undefined." (General Usage)
It's important to consider the context to understand the specific meaning of "undefined."