Plot quadratic functions and calculate their integral using Riemann sums
I really like this project because of what it suggests. It demonstrates that Etoys can be a powerful discovery tool for calculus concepts (in this case, integration). I could see giving math students a challenge to create an Etoys project that would calculate the area under a curve; this project would be a sample product. It also functions as a demonstration of integration. Nice conception and execution.
I do see an issue where the bottom of the integration is not the x-axis, but a line with a slope of about -1/9 (or y = -1/9x). Scale was set to 64 for both x and y; function being plotted was y = x^2; xmax was 9, xmin was -9.
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