We will use the given information to determine some features of the function, starting with the slope.
Slope
Consider what slope represents: it is a change in the x- and y-values of the graph.
slope=change iny/change inx
We are told that the dependent variable y decreases by 4 units every time the independent variable x increases by 2 units.
slope=-4/2 ⇔ slope=-2/1
y-intercept
Think of the point where the graph of an equation crosses the y-axis. The x-value of that ( x, y) coordinate pair is 0, and the y-value is the y-intercept. We know that the value of the function at 0 is -2.
f(0)=-2
Therefore the y-intercept is -2, and the graph intercepts the y-axis at the point ( 0, -2).
Graph
We now have enough information to graph the function. To start, plot the y-intercept and one other point using the slope we found above. By connecting these points with a line, we will form the graph of our equation.
x-intercept
Looking at our graph, we can also identify the x-intercept of this function.
The x-intercept of the function lies at the point (-1,0), so the x-intercept is -1.
