We recently started learning about derivatives in calculus. As sort of an introduction to the unit, we had to create GIFs of graphs demonstrating secant and tangent lines using desmos. This activity was insanely frustrating for me. It literally took me hours of messing with the graph to even get close to figuring it out, and when I finally did get it right, it was only because I was told exactly what to do. I can see the value of this activity, but I think it requires a little more guidance. I really wasn’t able to get anywhere on the first one without help from Mr. Cresswell. The people I was working with didn’t understand it either. In order to get the graphs to work, you had to enter the original equation as f(x) and use a general point of (a, f(a)) as well as a specific point on the curve to demonstrate the changing slope of the secant line. I got to this point pretty quickly, after Mr. Cresswell explained it. I knew I also needed to write an equation for a line connecting these two points that would move with (a,f(a)). However, could not figure out how to write this equation and make it stay connected to both points. Once again, I had to be instructed on how to make this work. Once I finally had a working graph, however, I was able to see how the slope of the secant lines and tangent line are related. As (a,f(a)) got closer to the set point on the curve, the slope of the secant line approached the slope of the tangent line at that point. Eventually, when the points were virtually the same, the secant line became the tangent line. This also worked for the next couple of GIFs when both points were moving along the curve. After I figured out the first graph, I was able to make the second pretty easily. All had to do was change the set point to (b,f(b)) and include this point into the slope equation. Then, I changed f(x) to 2*sin(x^3+x^2+x) to make the third GIF. This activity was a major struggle for me, but, in the end, the GIFs were a good demonstration of secant and tangent lines and how their slope changes and is related.