What is the slope of a horizontal line?

The slope of a <a href="https://www.wikiwhat.page/kavramlar/horizontal%20line">horizontal line</a> is always zero. This is because slope represents the <a href="https://www.wikiwhat.page/kavramlar/rate%20of%20change">rate of change</a> of the y-value with respect to the x-value. In a horizontal line, the y-value remains constant regardless of the x-value. Consequently, the rise (change in y) is always zero.

Using the slope formula, m = (y₂ - y₁) / (x₂ - x₁), for any two points on a horizontal line, y₂ and y₁ will be equal, making the numerator zero. Thus, m = 0 / (x₂ - x₁) = 0. Therefore, the <a href="https://www.wikiwhat.page/kavramlar/slope">slope</a> is zero.