[size=150]Can you see how a number pattern with a common difference in terms relates to a graph of a linear function when plotted in the cartesian coordinate system, with x corresponding to n (the position of a term) and y corresponding to the value of the term.[br][br]What if the [b]difference between terms [/b]is not constant (common), either [b]increasing or decreasing, [/b]will the points plotted be in a straight line like a linear function's ?[/size]