{Roma. 17. Love to learn. Love to teach.}

Making a complex world simple. Mostly a math blog. Some literature and science.

School in session. May be slow to post.

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Background Illustrations provided by: http://edison.rutgers.edu/
Reblogged from visualizingmath  520 notes

So a derivative is like picking two points on a graph and calculating the difference in the y-values and dividing by the difference in the x-values … when the two points you pick are infinitesimally close. Up above we’ve drawn a plot of temperature T versus distance x, and we’ve shown the derivative at three points.

The way you can picture a derivative is this: If you draw a straight line that barely touches the curve at one point only, then that line is called a tangent. And the derivative at a point tells you the slope of the tangent. Where the curve is steep, the slope is high (3) and where it’s not steep slope is low (1/3). (The -ve signs are because temp goes down as x increases.)

Reblogged from mathematica  37 notes

#### Help me out?

I’ve really started to notice when people use words co-opted from the mathematical jargon. So I’m making a list of mathematical words and phrases that people sometimes use in non-mathematical conversation:

• By definition
• QED (and the neologism “Quite Easily Done”)
• By parallel,…
• At right angles with
• Equilateral
• Trivial / nontrivial
• Without loss of generality,…
• As a corollary,…
• Continuous
• Map / project onto
• It follows that…
• If and only if
• Necessary and sufficient
• Parametrize
• Operates on
• Partition
• Double negative
• Tautology
• Equivalence
• By the transitive property (from liz011)

Soon we’ll all be speaking in propositional logic. Let us know if you have more, and we’ll add them! [CJH]

First of all, that first statement is an overgeneralization. Not every Chinese person is going to be skilled at math of course. It’s ignorant to go into these stereotypes.

But try this:

4,8,5,3,9,7,6.

Read them out loud to yourself. Now look away, and spend twenty seconds memorizing that sequence before saying them out loud again.

If you speak English, you have about a 50 percent chance of remembering that sequence perfectly If you’re Chinese, though, you’re almost certain to get it right every time.

Why is this?

One explanation is because the Chinese language allows them to read numbers faster.

Chinese number words are remarkably brief. Most of them can be said in less than 1/4th of a second (for instance, 4 is ‘si’ and 7 ‘qi’)

Their English equivalents—”four,” “seven”—are longer: pronouncing them takes about 1/3 of a second.

The English number system is also VERY illogical.

For example, right after the word 10, instead of saying one-ten, two-ten, three-ten we have different words like 11,12.

Not so in China, Japan and Korea. They have a logical counting system. Eleven is ten one. Twelve is ten two. Twenty-four is two ten four, and so on.

That difference means that Asian children learn to count much faster. Four year old Chinese children can count, on average, up to forty. American children, at that age, can only count to fifteen, and don’t reach forty until they’re 5 years old.

The regularity of their number systems also means that Asian children can perform basic functions—like addition—far more easily.

Ask an English seven-year-old to add thirty-seven plus twenty two, in her head, and she has to convert the words to numbers (37 + 22).

Ask an Asian child to add three-tens-seven and two tens-two, and no translation is necessary.

SOURCE: X