Quod Erat Demonstrandum

2014/02/21

某概率題

Filed under: NSS — johnmayhk @ 3:15 下午
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$\frac{C_2^7}{C_6^{11}}$

2014/02/20

平方和

Filed under: Fun — johnmayhk @ 11:44 下午
Tags:

$a_1,a_2,a_3,\dots a_n$

$b=\sqrt{a_2^2+a_3^2+\dots +a_n^2}$

$(a_1+bi)^m=P+Qi$

2014/02/18

小三數

Filed under: Family — johnmayhk @ 3:40 下午

「皮球售價 $28，比練習簿貴$15，若以 \$100 購買練習簿 3 本，應找回多少元？」

2014/02/17

無聊改卷後

Filed under: NSS — johnmayhk @ 10:40 下午

This is a standard question in a quiz:

Solve

$3^x=324-3^{x-1}$

One of my students gave the following so-called solution:

$3^x=3^5+3^4-3^{x-1}$

$x=5+4-x+1$ (more…)

2014/02/14

[FW] 微積分的哲學觀

Filed under: Report — johnmayhk @ 12:47 下午

2014/02/11

二項極限

Filed under: NSS,Pure Mathematics — johnmayhk @ 3:16 下午
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（圖片來源：Mathematics）

“…is a recently discovered beauty, probably in 2012…"

2014/02/10

無聊改卷後

Filed under: NSS — johnmayhk @ 5:55 下午

Suppose $2x^2-4x-a+1\ge 0$ for any real value of $x$, find the range of values of $a$.

2014/02/07

[TED] 費波那西數列的魔力

Filed under: Fun — johnmayhk @ 9:06 下午

2014/02/03

卡塔蘭

Filed under: Fun,NSS — johnmayhk @ 1:11 上午
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1,1,2,5,14,42,…

2014/02/01

某數型

Filed under: Fun — johnmayhk @ 5:59 下午
Tags:

2,3,4,…,12