## Section 4 Calculators

It might be useful to have a graphing calculator, and the standard recommendation is the Texas Instruments TI-84 Plus.

However, many choices of free "calculating device" can work too, including websites, phone apps and computer software, and I will demonstrate some of them. Two of my favorites are the online tools Desmos Graphing Calculator^{ 1 } and the Graphing and 3D calculators at Geogebra^{ 2 }.

In addition to that website interface, Desmos is available as a free app for iPhones, iPads^{ 3 }, and Android^{ 4 } devices. There are also several other tools at the Desmos website^{ 5 }, such as a Scientific Calculator^{ 6 }.

Such tools may be used for some homework and in-class exercises, but not on tests or the final exam.

`www.desmos.com/calculator/`

`www.geogebra.org/calculator`

`apps.apple.com/us/app/desmos-graphing-calculator/id653517540`

`play.google.com/store/apps/details?id=com.desmos.calculator`

`www.desmos.com`

`www.desmos.com/scientific`