Question

Which is the better definition of the “cube” of a number?
A real number that cannot be written as a simple fraction - the decimal goes on forever without repeating.
The result of using a whole number in a multiplication three times
A special value that, when used in a multiplication three times, gives that number
A number with no fractional part.
You can write them down like this: {..., -3, -2, -1, 0, 1, 2, 3, ...}

Answer 1

B isn't it?

Answer 2

squared is ^2 so cubed ^3

Answer 3

7^3 = 7x7x7

Answer 4

None of these answers is right.

"A real number that cannot be written as a simple fraction - the decimal goes on forever without repeating." This is the definition of an irrational number. A cube can be rational or irrational, so this is not helpful in saying what a "cube" is.

"The result of using a whole number in a multiplication three times." This is the least wrong of the answers. The problem is "whole." The cube of a number is the result of using the number three times in a multiplication. But this is true of ANY number. So if you removed the word "whole" and replaced "a" with "the" you would have a true statement.

"A special value that, when used in a multiplication three times, gives that number." This is the definition of a cube root. Since every number has a cube root and a cube, it is not very special.

"A number with no fractional part" This is a definition of an integer. Some cubes are integers. Some cube roots are integers. It is true that cube of an integer is an integer, but that is not helpful in defining what a cube is.

This item should be taken out and shot..