Читать книгу Algebra I All-in-One For Dummies - Mary Jane Sterling, Mary Sterling Jane - Страница 45

The absolute value operation, indicated by two vertical bars around a number, , is greatly related to the number line, because it tells you how far a number is from 0 without any regard to the sign of the number. The absolute value of a number is its value without a sign. The absolute value doesn’t pay any attention to whether the number is less than or greater than 0; it just determines how far it is from 0.

The formal definition of the absolute value operation is:

So, essentially, if a number is positive or 0, then its absolute value is exactly that number. If the number you’re evaluating is negative, then you find its opposite — or you make it a positive number.