Plotting and interpreting graphs _______________________________________________________________________________________________________________________6. Linear graph with a gradient. Direct proportion
The variable shown on the y-axis changes its value in the same proportion as the variable shown on the x-axis does. We can say that that variable A (distance in the graph) is directly proportional to B (time in the graph)There are two possibilities in these types of graphs: Graph 1. The value of A is zero when the value of B is also 0. The equation for the relationship: A = kB Graph 2. The value of A is not 0 When the value of B is. The graph starts at the point (0, A0). A0 is the value of A when B is 0.The equation for the relationship between A and B is: A = A0 + kB