Final answer:
A negative sign (-) is used to show that an event or activity has not taken place, indicating its absence or the opposite of an action.
Step-by-step explanation:
To show that an event or activity has not taken place, we use the negative sign (-). In mathematics, numbers can have either a positive (+ve) or a negative (-ve) sign to indicate their relation to zero. A negative sign means that the number is less than zero, which can symbolize the absence or the opposite of an action or event. For instance, a negative value of time might imply an event that occurred before the start of motion, or when dealing with the direction of motion, a negative sign is typically assigned to an object moving downward. In calculations, when two numbers multiplied have opposite signs, the answer has a negative sign, which also reflects that one aspect negates or does not exist in relation to the other.