385: How it Works

Explain xkcd: It's 'cause you're dumb.
(Difference between revisions)
Jump to: navigation, search
(the subheading helps the overview.)
(The math)
Line 11: Line 11:
  
 
===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 given answer {{w|π}} s just plain 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.
+
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
It's pi plus C, of course.
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 x2. (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 x2. Now, x3/3 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) x3/3 + 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.
comment.png add a comment!

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)

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)
Personal tools
Namespaces

Variants
Actions
Navigation
Toolbox

It seems you are using noscript, which is stopping our project wonderful ads from working. Explain xkcd uses ads to pay for bandwidth, and we manually approve all our advertisers, and our ads are restricted to unobtrusive images and slow animated GIFs. If you found this site helpful, please consider whitelisting us.

Want to advertise with us, or donate to us with Paypal or Bitcoin?