A linear function is a function that can be written in the form \(f(x) = mx+b\). The graph of a linear equation is a line. This line will pass through the \(y\)-axis at the point \((0,b)\), and will have slope \(m\). The slope gives us an idea of the "rate of change" of the function. If the slope is positive, the line is increasing from left to right, with larger slopes yielding steeper lines. If the slope is negative, the line is decreasing.

Drag the "handles" to change the graph. The slope and \(y\)-intercept of the function will update. The triangular region attached to the graph depicts the slope, which is the change in \(y\)-values per 1 horizontal unit. You can zoom in and out of the graph using the slider, and recenter the graph by dragging the entire plane.

This applet was created using JavaScript and the Konva graphics library.