What is the multiplicative inverse of 2

What is the multiplicative inverse of 2?

The Correct Answer and Explanation is:

ChatGPT said:

The multiplicative inverse of a number aaa is the number that, when multiplied by aaa, gives the result 1. In mathematical terms, the multiplicative inverse of aaa is denoted as a−1a^{-1}a−1, and it satisfies the equation:a×a−1=1a \times a^{-1} = 1a×a−1=1

For the number 2, we need to find the number xxx such that:2×x=12 \times x = 12×x=1

To solve for xxx, we divide both sides of the equation by 2:x=12x = \frac{1}{2}x=21​

Thus, the multiplicative inverse of 2 is 12\frac{1}{2}21​.

Why is this the multiplicative inverse?

When we multiply 2 by 12\frac{1}{2}21​, we get:2×12=12 \times \frac{1}{2} = 12×21​=1

This satisfies the definition of a multiplicative inverse because the result of the multiplication is 1, which is the identity element for multiplication.

General Concept

The concept of a multiplicative inverse extends beyond just the number 2. For any non-zero number aaa, its multiplicative inverse is given by:a−1=1aa^{-1} = \frac{1}{a}a−1=a1​

This holds true for all real numbers (except zero), and it’s essential in algebra and number theory, especially when solving equations or simplifying expressions.

In summary, the multiplicative inverse of 2 is 12\frac{1}{2}21​, and this property is part of the broader concept of inverses in mathematics.

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