https://ihatedesmos.com/blog/ Notes on graphing, numerical accuracy and mathematics from the makers of ihateDesmos. en https://ihatedesmos.com/blog/why-graphing-calculators-draw-vertical-lines/ https://ihatedesmos.com/blog/why-graphing-calculators-draw-vertical-lines/ Tue, 20 Oct 2026 12:00:00 GMT The vertical lines at the asymptotes of tan x and 1/x aren’t part of the graph. Why they appear, why more samples don’t help, and what does. https://ihatedesmos.com/blog/interval-arithmetic-certified-plotting/ https://ihatedesmos.com/blog/interval-arithmetic-certified-plotting/ Tue, 20 Oct 2026 12:00:00 GMT Sampling plotters can miss curves that touch zero without crossing it. Interval arithmetic computes with ranges, so a plotter can prove where a curve is. https://ihatedesmos.com/blog/floating-point-sin-pi/ https://ihatedesmos.com/blog/floating-point-sin-pi/ Tue, 20 Oct 2026 12:00:00 GMT Computers say sin(π) = 1.22 × 10⁻¹⁶ and 0.1 + 0.2 = 0.30000000000000004. Why floating point does this, and how a calculator gives the expected answer. https://ihatedesmos.com/blog/how-to-draw-a-slope-field/ https://ihatedesmos.com/blog/how-to-draw-a-slope-field/ Tue, 20 Oct 2026 12:00:00 GMT How to draw a slope field by hand, step by step: compute the slopes, sketch solution curves, find equilibria, and match equations to slope fields. https://ihatedesmos.com/blog/regression-confidence-bands/ https://ihatedesmos.com/blog/regression-confidence-bands/ Tue, 20 Oct 2026 12:00:00 GMT Four data sets with the same regression line and the same R², and completely different stories. How to read residuals, standard errors and bands. https://ihatedesmos.com/blog/domain-coloring-complex-functions/ https://ihatedesmos.com/blog/domain-coloring-complex-functions/ Tue, 20 Oct 2026 12:00:00 GMT A complex function needs four dimensions to graph. Domain colouring fits it in a picture: hue for the angle, brightness for the size. Reading zeros and poles. https://ihatedesmos.com/blog/best-free-graphing-calculators/ https://ihatedesmos.com/blog/best-free-graphing-calculators/ Tue, 20 Oct 2026 12:00:00 GMT Desmos, GeoGebra, NumWorks, Wolfram|Alpha and ihateDesmos compared: what each free graphing calculator does best, and which to use when. https://ihatedesmos.com/blog/graphing-calculator-tips/ https://ihatedesmos.com/blog/graphing-calculator-tips/ Tue, 20 Oct 2026 12:00:00 GMT Restrict domains, draw families with lists, graph derivatives, find intersections, fit data and use units: 18 practical graphing calculator tips.