Mathematics is my life! from Sebastian Linda on Vimeo.
2011/09/30
2011/09/24
[FW] Surprises in Mathematics
Featuring Dr. Stan Wagon Professor of Mathematics – Macalester College. There is no better way to get someone’s attention than with an assertion that just seems obviously wrong. Math is full of such things. The talk presents several surprising even shocking things from elementary mathematics such as: A square wheel that rolls perfectly smoothly. A device that uses a normal rotating crankshaft to drill perfect square holes. An application of a non-circular wheel to sewage disposal. A shocking cake puzzle. Surprising new formulas for π. Benford’s mysterious law of first digits. The Banach-Tarski Paradox with constructible pieces.
2011/09/23
2011/09/19
(x=2 or x=-2) implies x^2=-4?
Just a question asked by a student, Thomas.
multiply the above, yield
strange?
He puzzled that, why (more…)
2011/09/08
食數
我是「數食」者,對飲食不及「八零、九零、零零」後講究。以「飲飲食食」作為學科的包裝/重點(諸如 high tea 學英文之類),常有之。昨早看了「吃你的數學功課」作者的短片:
http://wusa9.com/news/article/165892/373/Helping-Kids-Love-Math-By-Eating-It
或有些「亮點」吧。
2011/09/06
Can you draw…
以下是某道 core math 的題:
Can you draw a triangle with area of 100 , and two of its sides are 10 cm and 16 cm long? Explain briefly.
(在絕對平面上)理論上,是畫不到的。因為
是無解的。
若問: (more…)