Math, Mathematics, Mathematics Education, Calculus, Learning.
subtract the second y-value from the first to get our “rise”, f(x₂)-f(x₁). Similarly, the “run” of the graph is the difference in x-values, so we can subtract the second x-value from the first to get our “run”, x₂-x₁. Putting our “rise” over our “run” results in our slope, so we can write a formula