This is a discovery lesson using the TI graphing calculator. Students graph various lines and record their results. They answer questions leading them to understand the slope and y-intercept of an equation and how it affects the graph. Students should know terminology about coefficients and constant terms. This lesson was designed to take place after students have a basic understanding of slope and what the x and y intercepts of a line are. This is a lead in to use before they learn slope-intercept form.