# Difference between revisions of "385: How it Works"

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===The math=== | ===The math=== | ||

− | The mathematics displayed is neither {{w|semantically}} nor {{w|syntactically}} correct. To begin with, there should be a ''dx'' after x<sup>2</sup>. (That's easy enough to forget.) Now we have an {{w|indefinite integral}} on the left hand side. | + | The mathematics displayed is neither {{w|semantically}} nor {{w|syntactically}} correct. To begin with, there should be a ''dx'' after x<sup>2</sup>. (That's easy enough to forget.) Now we have an {{w|indefinite integral}} on the left hand side. There is still something missing from the equation, however. |

+ | It could be possible that {{w|π}} is just wrong: What we want is a {{w|Function (mathematics)|function}}, whose {{w|derivative}} is x<sup>2</sup>. Now, x<sup>3</sup>/3 satisfies this condition. However, since adding a {{w|constant (mathematics)|constant}} to a function does not change its derivative, the full answer is (any function on the form) x<sup>3</sup>/3 {{w|Constant of integration|+ C}}, where C is any fixed number. The "plus a constant"-part is very easy to forget, and might even be omitted by a (sloppy) professional mathematician. So if someone really gave the answer π, "you forgot to add a constant" would be a pretty funny remark, cause in one way it's true, but on the other hand it wouldn't quite be the main thing to worry about. | ||

+ | Another possibility is that more was forgotten on the left side of the equation -- bounds of integration. If there were a 0 below the integral and a cube root of 3π above the integral symbol, the answer π would be correct. In this case, however, pi+C would be incorrect. | ||

Congratulations, now you can also get [http://www.netfunny.com/rhf/jokes/old90/constant.html this classical joke]! | Congratulations, now you can also get [http://www.netfunny.com/rhf/jokes/old90/constant.html this classical joke]! |

## Revision as of 22:08, 11 March 2013

How It Works |

Title text: It's pi plus C, of course. |

## Explanation

The comic reveals discriminative jargon against women when doing a task. When a guy does something wrong, it's his own mistake. When a girl does something wrong, it is taken as a confirmation that girls are inferior.

### The math

The mathematics displayed is neither semantically nor syntactically correct. To begin with, there should be a *dx* after x^{2}. (That's easy enough to forget.) Now we have an indefinite integral on the left hand side. There is still something missing from the equation, however.
It could be possible that π is just wrong: What we want is a function, whose derivative is x^{2}. Now, x^{3}/3 satisfies this condition. However, since adding a constant to a function does not change its derivative, the full answer is (any function on the form) x^{3}/3 + C, where C is any fixed number. The "plus a constant"-part is very easy to forget, and might even be omitted by a (sloppy) professional mathematician. So if someone really gave the answer π, "you forgot to add a constant" would be a pretty funny remark, cause in one way it's true, but on the other hand it wouldn't quite be the main thing to worry about.
Another possibility is that more was forgotten on the left side of the equation -- bounds of integration. If there were a 0 below the integral and a cube root of 3π above the integral symbol, the answer π would be correct. In this case, however, pi+C would be incorrect.

Congratulations, now you can also get this classical joke!

## Transcript

- [Cueball and an friend stand at a blackboard. The friend is writing, in standard mathematical notation, that the integral of x squared equals pi. No differential or bounds are given for the integral.]
- Cueball: Wow, you suck at math.
- [The same scene, except the writer is Megan.]
- Cueball: Wow, girls suck at math.

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# Discussion

I will admit, after I finished Calc 1, I came across this yet again via the random button, and kind of rolled my eyes. Then I read the title text, and this became one of my favorite comics. --140.198.42.64 00:19, 20 March 2013 (UTC)

- The same thing happened to me. This is definitely one comic where a little bit of knowledge about the subject really makes the joke. --108.162.215.125 06:59, 31 May 2016 (UTC)

This type of generalization also has a special name called "Stereotype threat". Research shows that women/girls who are good at math (identify as good at math) will do worse on hard math questions when they think (consciously or unconsciously) that her own personal failings will reflect on the negative stereotype. (Real example: a group of professors asked SAT testing body to ask for demographic questions (gender/race) after the test instead of before.) 108.162.254.107 04:15, 18 June 2014 (UTC)

I don't really think that pi + C is different from just C. Pi is a constant anyway! 173.245.48.96 (talk) *(please sign your comments with ~~~~)*

In popular culture: it appeared twice in the grade 10 english module in the philippines,and without the correct citation. p.s. what should i do? 108.162.215.10 08:33, 16 July 2015 (UTC)

- xkcd is released under a Creative Commons license that allows any redistribution but requests a citation if you are making money from it. I think it's fine unless they're ripping Randall off. That's right, Jacky720 just signed this (talk | contribs) 23:53, 5 May 2018 (UTC)
*reads license*okay, no commercial redistribution, and give appropriate credit. Ask them nicely to add a citation? Idk. That's right, Jacky720 just signed this (talk | contribs) 23:57, 5 May 2018 (UTC)

Maybe include the phrase confirmation bias?108.162.218.53 20:27, 21 February 2016 (UTC)

Megan wasn't finished with the equation yet. That's why her hand is still up at the board. She can still produce a correct - even if strange - equation. 162.158.90.189 (talk) *(please sign your comments with ~~~~)*

One thing I noticed is if you just take the letters of "Pi" and "c", it makes "Pic". "Pic" is a way to shorten the word "Picture"!108.162.245.115 18:30, 27 September 2016 (UTC)