Question

Which of the following is not a true statement about absolute value?

A. Absolute value is always positive.
B. The absolute value of zero is undefined.
C. Absolute value is a measure of distance from zero.
D. The absolute value of a negative number is a positive number.

Answer 1

I think the correct answer among the choices listed above is option B. An absolute value is a measure of distance of a number from zero. It will always have a positive value. The absolute value of a negative number is always the positive value.

Answer 2

Answer: option B. The absolute value of zero is undefined.

Explanation:

The absolute value of a number is the nonnegative value of the number, no matter its sign. For example, the absoulte value of 100 is 100 and the absolute value of - 100 is 100, because the sign is disregarded, you only take the value without the sign.

The absolutle value of zero is zero (zero has no sign and the absolute value either).

The absolute value function is indicated by the use of two vertical lines, one in front and one after the number, | |.

Followiing with the previous example, the notation is

| 100 | = 100, and | - 100 | = 100.

The formal definition of the absolute value function:

|x| = x for x ≥ 0, note that this include zero.

|x| = − x for x < 0, note that - x is positive, since x is negative.