High School

Which monomial is a perfect cube?

A. [tex]1x^3[/tex]
B. [tex]3x^3[/tex]
C. [tex]6x^3[/tex]
D. [tex]9x^3[/tex]

Answer :

To determine which monomial is a perfect cube, we need to look at the coefficients of the monomials provided. A number is a perfect cube if it can be expressed as [tex]\( n^3 \)[/tex] where [tex]\( n \)[/tex] is an integer.

Let's examine each coefficient:

1. Coefficient 1:
- [tex]\(1\)[/tex] can be written as [tex]\(1^3\)[/tex] because [tex]\(1 \times 1 \times 1 = 1\)[/tex].

2. Coefficient 3:
- The cube root of [tex]\(3\)[/tex] is not an integer, so [tex]\(3\)[/tex] is not a perfect cube.

3. Coefficient 6:
- The cube root of [tex]\(6\)[/tex] is not an integer, so [tex]\(6\)[/tex] is not a perfect cube.

4. Coefficient 9:
- The cube root of [tex]\(9\)[/tex] is not an integer, so [tex]\(9\)[/tex] is not a perfect cube.

From the list above, only the monomial with coefficient [tex]\(1\)[/tex], or [tex]\(1x^3\)[/tex], is a perfect cube because [tex]\(1\)[/tex] is a perfect cube.

Therefore, the monomial that is a perfect cube is [tex]\(1x^3\)[/tex].