Horizontal lines have slope 0
Horizontal lines have slope 0 is a Grade 7 algebra concept in Big Ideas Math Advanced 2, Chapter 4: Graphing and Writing Linear Equations. A horizontal line y equals b has slope 0 because the rise is always 0 for any change in x. In slope-intercept form, the equation of a horizontal line is y equals 0 times x plus b, simplified to y equals b.
Key Concepts
The slope of a horizontal line, $y = b$, is 0.
Common Questions
Why does a horizontal line have slope 0?
A horizontal line has no rise — the y-value stays constant regardless of x. Since slope equals rise divided by run and the rise is 0, the slope is 0 divided by any number, which equals 0.
What is the equation of a horizontal line?
A horizontal line has equation y equals b where b is the constant y-value. For example, y equals 5 passes through every point where y is 5, regardless of x.
What does slope 0 look like on a graph?
A slope of 0 appears as a perfectly flat horizontal line parallel to the x-axis. There is no upward or downward tilt.
What textbook covers horizontal lines and slope 0 in Grade 7?
Big Ideas Math Advanced 2, Chapter 4: Graphing and Writing Linear Equations covers horizontal lines, their equations, and why their slope is 0.