北京 景山 学校 数学系
Elective / Pre-Calculus @ MATHEMATICS @ Senior 1.4  。2010-11

jiguanglaoshi@gmail.com

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[6] April
[updated : 2011/05/18]
Date
Activities / Objectives
 Images / Home work / Assignments
Remarks / Images
References  / Links

Friday

April 1st

11:25 -12:05

  • Return of Exercise 2.3 / Recursive sequence with an arithmetic auxiliairy sequence to prove the limit.

  • Presentation of the problem of the Hanoï towers :
    • construction of the recursive formula : Mn = 2Mn-1 + 1
      where
      Mn = represents the minimum number of moves.
    • Demo of the direct formula
               Mn = 2n - 1

  • Problem of the Chess Board and the amount of rice to be stacked on each box by doubling the previous quantity : The total number of rice grains on the 64th box would be 263
    and the total number of rice grains on the board would be equal to 
                   M64 = 264 - 1
    (same as the number of moves in the Hanoï towers)

  •  Study of the general formula of the sum of the first nth terms of a geometric sequence : (if q ≠ 1)
    Sn_Geom
  • Study of the limits of Sn  with |q| < 1
               limSn
     the limit of qn = 0 when
    |q| < 1 and  n-> ∞
Game of the Hanoï Towers

hanoi
Mn = Mn-1 + 1 + Mn-1
Mn  + 1= 2Mn-1 + 2 = 2(Mn-1 + 1)
Mn + 1 = 2n


* * *
How to make 2 candy bars with 1 :
(April's 1st Fool's day ...)
Take a candy bar, chop it up in two equal parts and each new piece in two ... indefinitely,
then glue them back together ... on top of the first half, then ... you get TWO candy bars instead of one ...

Candy's candy bar

candy bar


The puzzle was invented by the French mathematician Édouard Lucas in 1883. There is a legend about an Indian temple which contains a large room with three time-worn posts in it surrounded by 64 golden disks. Brahmin priests, acting out the command of an ancient prophecy, have been moving these disks, in accordance with the rules of the puzzle, since that time. The puzzle is therefore also known as the Tower of Brahma puzzle. According to the legend, when the last move of the puzzle is completed, the world will end.[1] It is not clear whether Lucas invented this legend or was inspired by it.

If the legend were true, and if the priests were able to move disks at a rate of one per second, using the smallest number of moves, it would take them 264−1 seconds or roughly 585 billion years;[2] it would take 18,446,744,073,709,551,615 turns to finish ...

Similarly see
Problem of the Chess Board
there is a legend about
the quantity of rice grains represented by this number would cover more than three times the whole surface of the Earth



Game of the Hanoï Towers

About the chess board and the Formula of Sn for a Geometric sequence : see
高中数学
#5 - B - 2005
p. 51-52
Problem of the Chess Board
When the creator of the game of chess (in some tellings an ancient Indian mathematician, in others a legendary dravida vellalar named Sessa or Sissa) showed his invention to the ruler of the country, the ruler was so pleased that he gave the inventor the right to name his prize for the invention. The man, who was very wise, asked the king this: that for the first square of the chess board, he would receive one grain of wheat (in some tellings, rice), two for the second one, four on the third one, and so forth, doubling the amount each time. The ruler, arithmetically unaware, quickly accepted the inventor's offer, even getting offended by his perceived notion that the inventor was asking for such a low price, and ordered the treasurer to count and hand over the wheat to the inventor. However, when the treasurer took more than a week to calculate the amount of wheat, the ruler asked him for a reason for his tardiness. The treasurer then gave him the result of the calculation, and explained that it would be impossible to give the inventor the reward. The ruler then, to get back at the inventor who tried to outsmart him, told the inventor that in order for him to receive his reward, he was to count every single grain that was given to him, in order to make sure that the ruler was not stealing from him.



Wednesday


April 6

11:25 -12:05
  • Presentation of the Fibonacci's sequence
    fib_seqx

    Fn+1= Fn + Fn-1   ;  F1 = F2 = 1

  • Exercises on the Fibonacci's numbers
    and it's relationship with the Golden number.


Preparation of TEST

of Friday April 8th
Review all previous exercises
1.1-1.2-2.1-2.2-2.3-2.4
about recursive or non recursive sequences
+ formulas of the Geometric series

Dowload the .ppt prepared by
吴鹏老师
for his visit to my class
at Ecole alsacienne
in January 2009



Fib

Fibonacci (XIIIth c.)
Review :

Arith. & Geom. Sequences Memo

Ex. 1.1 & 1.2 ANSWERS

Ex. 2.1 & 2.2 ANSWERS

Ex. # 2.3 ANSWERS

Ex. # 2.4 The Chaos Theory

吴 鹏老师.ppt

Exercises on Fibonacci's # 2.5


Friday

April 8

11:25 -12:05


TEST

about recursive
sequences


fibTA

TAU

TAV



Test A


Test B


Wednesday

April 13

11:25 -12:05




  • Return graded Tests

  • Tests Answers
graphTA

TESTS RESULTS
(maximum score : 40 pts)

32 ≤ N ≤ 40 := 10%

28 ≤ N ≤ 31 := 20%

24 ≤ N ≤ 27 := 22%

00 ≤ N ≤ 23 := 48%



Friday

April 15

11:25 -12:05


Geometric Series in ... Geometry (I)


Study of the finite
Length of an Infinite Spiral
spirale_inf




Geometric Series in ... Geometry (I)



Wednesday

April 20

11:25 -12:05


Geometric Series in ... Geometry (II)

koch_Pn

koch_An

koch





Comparison
of the inifinite length
of the perimeter
with the
finite measure of the area







Geometric Series in ... Geometry (II)


Koch Snowflake Answers






Friday


April 22

11:25 -12:05

Geometric Series in ... Geometry (III)


SR2

SR2





Geometric Series in ... Geometry (III)


Riemann's Integral Sum ANSWERS

Wednesday
April 27

11:25 -12:05


Mid-Term Exams
(general - Non elective subjects)
Friday
April 29
11:25 -12:05