THE GOLDEN RATIO AND THE FIBONACCI NUMBERS Common Measures 1 foot - - PowerPoint PPT Presentation

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the golden ratio and the fibonacci numbers common measures
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THE GOLDEN RATIO AND THE FIBONACCI NUMBERS Common Measures 1 foot - - PowerPoint PPT Presentation

THE GOLDEN RATIO AND THE FIBONACCI NUMBERS Common Measures 1 foot 2 feet 3 feet 3 2 Ratio = Ratio = 2 1 Common measure = 1 foot 25 inches 11 inches 36 inches 36 25 Ratio = Ratio = 25 11 Common measure = 1 inch a b a + b


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SLIDE 1

THE GOLDEN RATIO AND THE FIBONACCI NUMBERS

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SLIDE 2

Common Measures

3 feet 2 feet 1 foot 3 2 Ratio = Common measure = 1 foot 2 1 Ratio =

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SLIDE 3

36 inches 25 inches 11 inches 36 25 Ratio = Common measure = 1 inch 25 11 Ratio =

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SLIDE 4

a b

Incommensurable!

𝑏 + 𝑐 𝑏 = 𝑏 𝑐 a + b (no fraction of a foot can be used to measure this distance)

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SLIDE 5

οͺ

1.618033988749894…

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SLIDE 6

The origins of οͺ are shrouded in the mists of time

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SLIDE 7

The Golden Ratio: οͺ

  • In modern times is denoted by the symbol phi: οͺ
  • Known to Euclid (300 B.C.) as a result of solving:
  • A number of painters and architects have used

the golden ratio in their work

  • The length of a diagonal of a regular pentagram,

whose sides have unit length, is οͺ

  • Occurs in nature – represents a growth pattern

𝑦2 βˆ’ 𝑦 βˆ’ 1 = 0

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SLIDE 8

Legend and Speculation

  • Was known to the ancient Egyptians.
  • Was used to form the dimensions of the

Great Pyramids of Egypt.

  • Was applied to the design of the Parthenon.
  • Was used in the design of Notre Dame in

Paris.

  • Was used in the construction of the Taj

Mahal.

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SLIDE 9

The Parthenon

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SLIDE 10

Ratio of a Rectangle

a b

𝑏 𝑐 Ratio =

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SLIDE 11

Another Ratio

a a b

Ratio = 𝑏 + 𝑐 /𝑏 These two rectangles have a divine proportion if: 𝑏 + 𝑐 𝑏 = 𝑏 𝑐

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SLIDE 12

The Algebra

𝑏 + 𝑐 𝑏 = 𝑏 𝑐 𝑐 𝑏 + 𝑐 = 𝑏2 𝑏2 βˆ’ 𝑏𝑐 βˆ’ 𝑐2 = 0 Letting 𝑐 = 1 gives us: 𝑏2 βˆ’ 𝑏 βˆ’ 1 = 0 Whose only positive solution is οͺ

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SLIDE 13

Golden Ratio

  • Numerically the golden ratio is:
  • This comes from solving 𝑦2 βˆ’ 𝑦 βˆ’ 1 = 0 using

the quadratic formula:

  • All rectangle pairs that are in divine proportion

to each other will have this ratio. οͺ =

1+√5 2

= 1.61803 …

βˆ’π‘ Β± 𝑐2 βˆ’ 4𝑏𝑑 2𝑏

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SLIDE 14

a

Ratio = 𝑏 + 𝑐 /𝑏 If these two rectangles have a divine proportion then:

𝑏+𝑐 𝑏 = 𝑏 𝑐 = οͺ

a b

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SLIDE 15

Fibonacci Numbers

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SLIDE 16

The Original Problem

  • Stated by Fibonacci (whose original name

was Leonardo of Pisa) in the year 1202

  • Gives a recursive rule for computing the total

number of rabbit pairs under β€œideal” reproductive circumstances.

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SLIDE 17

Problem Statement

  • Start with a rabbit pool containing one pair of newly born

rabbits (one male and one female)

  • A newly born rabbit takes one month to reach reproductive

maturity

  • The gestation period of a reproductively mature female

rabbit is one month

  • A female rabbit will always give birth to two rabbits – one

male and one female

οƒΊ This newly born pair is added to the rabbit pool

  • Question: How big is the rabbit pool after

οƒΊ 12 months? οƒΊ n months?

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SLIDE 18

Young Pair Mature Pair Mature Pair Mature Pair Young Pair Mature Pair Mature Pair Mature Pair Month 1 Young Pair Mature Pair Mature Pair Mature Pair Young Pair Mature Pair Mature Pair Mature Pair Month 2 Month 3 Month 4

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SLIDE 19

Fibonacci Sequence

  • Starting from 1
  • Starting from 0

1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, … 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, …

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SLIDE 20

The pedal count of many flowers are Fibonacci numbers (this is a known growing pattern)

In Flowers

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SLIDE 21

,2,3,5,8,13,21,34,55,89,…

white calla lily

1

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SLIDE 22

1, ,3,5,8,13,21,34,55,89,… 2

Euphorbia

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SLIDE 23

1,2, ,5,8,13,21,34,55,89,… 3

Trillium

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SLIDE 24

1,2,3, ,8,13,21,34,55,89,…

Buttercup

5

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SLIDE 25

1,2,3,5, ,13,21,34,55,89,…

Bloodroot

8

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SLIDE 26

1,2,3,5,8, ,21,34,55,89,… 13

Black eyed Susan

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SLIDE 27

1,2,3,5,8,13, ,34,55,89,…

Shasta Daisy

21

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SLIDE 28

1,2,3,5,8,13,21, ,55,89,… 34

Field Daisies

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SLIDE 29

1,2,3,5,8,13,21,34, , ,… 55 89

Michelmas Daisies

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SLIDE 30

lim

π‘œβ†’βˆž

𝑔𝑗𝑐 π‘œ + 1 𝑔𝑗𝑐 π‘œ = οͺ

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SLIDE 31

fib(n+1) fib(n)

Approaching the Golden Ratio

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SLIDE 32

1, 1, 2, 3, 5, 8, 13, 21, 34, …

οͺ

1 1 2 1 3 2 5 3 8 5 13 8 