State, true or false:
The y-axis is the vertical number line.

Answer

To determine whether the statement "The y-axis is the vertical number line" is true or false, we can follow these steps:

1. **Understand the Coordinate System**: In a Cartesian coordinate system, there are two axes: the x-axis (horizontal) and the y-axis (vertical).

2. **Identify the Y-Axis**: The y-axis is the line that runs vertically through the origin (0,0) of the coordinate plane. It represents the values of y in a coordinate pair (x, y).

3. **Examine the Numbering of the Y-Axis**: The y-axis is indeed numbered. It extends from negative infinity (downwards) to positive infinity (upwards), which means it includes all real numbers.

4. **Conclusion**: Since the y-axis is vertical and represents a range of values like a number line, we can conclude that the statement is true.

Final Answer: True

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