# Fun Math Links

• Learn how to "prove" that 2 = 1 and 1 = -1. If such things could actually be proven, any mathematical statement could be proven (for example, 4 = 10). Personally, I have a few of these "proofs" memorized as they are fun to mention when discussing math and the rigors of mathematical deductive reasoning, and I am sure to also memorize the mathematical fallacies where the "proofs" go wrong.

• Fun number tricks!

# Free Math Tools

• Google is a handy calculator! Try typing
c/(30+2E2) in km/h
where c is interpreted as the speed of light in vacuum, and 2E2 is scientific notation for 200. Also, try stuff like
earth radius
1 AU in lightyears
y = cos(x)
z = x^2 + y^2
Sadly, Google has been having sporadic behavior over the past few years, so I wouldn't depend on it as a calculator. Just know that it's there if you want to try a quick calculation.

• WolframAlpha is the greatest thing ever. This can do whatever Google can do, so try typing any of the above examples. Or, try the following examples...
x^2 + 2 x + 3 = 3
sin^2(x) + cos^2(x)
integrate x^2 from 0 to 2
int a*x^3 {x,0,2}
y' = y
You can add this site to your search bar on your favorite web browser! Or, you can spend a couple dollars and buy the app for your mobile device turning your phone into a powerful computer! Note that viewing the site on a mobile device has limited functionality because they want you to buy the app, and note that buying the app still doesn't give you a pro subscription.

• If you want a graphing tool that doesn't require Internet access, the Desmos Graphing Calculator is a great free app (in addition to the free website I just linked to)! Note that nearly all computers and smartphones already come with a free (non graphing) scientific calculator.

# General Science 