# 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. |

− | + | ||

− | + | The answer {{w|π}} is just nonsensical: 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. | |

+ | |||

+ | It is also possible to fix the equation by adding [http://www.mathwords.com/b/bounds_of_integration.htm bounds of integration], so that {{w|π}} becomes the area below a section of the curve x<sup>2</sup>. The bounds would have to be somewhat awkward, like 0 as the lower and the cube root of 3*π as the upper. | ||

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 11:12, 12 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.

The answer π is just nonsensical: 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.

It is also possible to fix the equation by adding bounds of integration, so that π becomes the area below a section of the curve x^{2}. The bounds would have to be somewhat awkward, like 0 as the lower and the cube root of 3*π as the upper.

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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