Why sin 80xlooks like sin xon some graphing calculators
J. Zeng, Thomas J. Osler · International Journal of Mathematical Education in Science and Technology · 2005
In rare cases, the use of advanced mathematical calculators can give incorrect results. One such error occurs with graphing calculators because the screen is not continuous, but a rectangular array of pixels. On some frequently used calculators, the graph of sin 80x looks like sin x. We also study other related examples.