Question

generalize a certain number is both a perfect square and a perfect cube. will its sqaure root and its cube root always be different numbers. explain

Answers

GPT-4o mini
A number that is both a perfect square and a perfect cube is known as a perfect sixth power. This is because a number \( n \) can be expressed as:

- A perfect square if \( n = a^2 \) for some integer \( a \).
- A perfect cube if \( n = b^3 \) for some integer \( b \).

For \( n \) to be both, it must satisfy \( n = c^6 \) for some integer \( c \) (since the least common multiple of 2 and 3 is 6).

Now, let's consider the relationships between its square root and cube root:

1. **Square root** of \( n \):
\[
\sqrt{n} = \sqrt{c^6} = c^3
\]

2. **Cube root** of \( n \):
\[
\sqrt[3]{n} = \sqrt[3]{c^6} = c^2
\]

In general, for any integer \( c \):

- The square root of \( n \) is \( c^3 \).
- The cube root of \( n \) is \( c^2 \).

Now we can examine under what conditions \( c^3 \) and \( c^2 \) are equal or different:

- **If \( c = 1 \)**: Then \( c^3 = 1^3 = 1 \) and \( c^2 = 1^2 = 1\). In this case, the square root and cube root are the same.

- **If \( c > 1 \)**: Then \( c^3 > c^2 \) because for any integer greater than 1, \( c^3 \) (which is \( c \times c \times c \)) grows faster than \( c^2 \) (which is \( c \times c \)). Thus, in this case, the square root and cube root will differ.

- **If \( c < 1 \)**: Since \( c \) is non-negative, we consider only \( c = 0 \), which gives \( \sqrt{0} = 0 \) and \( \sqrt[3]{0} = 0\), making them equal again.

In conclusion, the square root and cube root of a number that is both a perfect square and a perfect cube will be equal only when \( c = 1 \). For all integers \( c > 1 \), the square root and cube root will be different, and for \( c = 0 \), they are also the same. Thus, for numbers that are perfect sixth powers where \( c > 1 \), the square root and cube root are always different.

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