The set ` {x in R : 1 le x lt 2}` be written as `"……………"` .

Explanation

To express the set \( \{ x \in \mathbb{R} : 1 \leq x < 2 \} \) in interval notation, we follow these steps:

1. **Identify the bounds of the set**: The set is defined for \( x \) such that \( 1 \leq x < 2 \). This means that \( x \) can take values starting from 1 (inclusive) up to, but not including, 2.

2. **Use interval notation**: In interval notation, we represent the lower bound (1) with a square bracket [ ] to indicate that it is included in the set, and the upper bound (2) with a parenthesis ( ) to indicate that it is not included in the set.

3. **Write the interval**: Therefore, the interval can be written as \( [1, 2) \).

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