Pascal`s Triangle Essay, Research Paper

Blas? Pacal was born in France in 1623. He was a child prodigy and was

fascinated by mathematics. When Pascal was 19 he invented the first calculating

machine that actually worked. Many other people had tried to do the same but did

not succeed. One of the topics that deeply interested him was the likelihood of

an event happening (probability). This interest came to Pascal from a gambler

who asked him to help him make a better guess so he could make an educated

guess. In the coarse of his investigations he produced a triangular pattern that

is named after him. The pattern was known at least three hundred years before

Pascal had discover it. The Chinese were the first to discover it but it was

fully developed by Pascal (Ladja , 2). Pascal’s triangle is a triangluar

arrangement of rows. Each row except the first row begins and ends with the

number 1 written diagonally. The first row only has one number which is 1.

Beginning with the second row, each number is the sum of the number written just

above it to the right and the left. The numbers are placed midway between the

numbers of the row directly above it. If you flip 1 coin the possibilities are 1

heads (H) or 1 tails (T). This combination of 1 and 1 is the firs row of

Pascal’s Triangle. If you flip the coin twice you will get a few different

results as I will show below (Ladja, 3): Let’s say you have the polynomial x+1,

and you want to raise it to some powers, like 1,2,3,4,5,…. If you make a chart

of what you get when you do these power-raisins, you’ll get something like this

(Dr. Math, 3): (x+1)^0 = 1 (x+1)^1 = 1 + x (x+1)^2 = 1 + 2x + x^2 (x+1)^3 = 1 +

3x + 3x^2 + x^3 (x+1)^4 = 1 + 4x + 6x^2 + 4x^3 + x^4 (x+1)^5 = 1 + 5x + 10x^2 +

10x^3 + 5x^4 + x^5 ….. If you just look at the coefficients of the polynomials

that you get, you’ll see Pascal’s Triangle! Because of this connection, the

entries in Pascal’s Triangle are called the binomial coefficients.There’s a

pretty simple formula for figuring out the binomial coefficients (Dr. Math, 4):

n! [n:k] = ——– k! (n-k)! 6 * 5 * 4 * 3 * 2 * 1 For example, [6:3] =

———————— = 20. 3 * 2 * 1 * 3 * 2 * 1 The triangular numbers and

the Fibonacci numbers can be found in Pascal’s triangle. The triangular numbers

are easier to find: starting with the third one on the left side go down to your

right and you get 1, 3, 6, 10, etc (Swarthmore, 5) 1 1 1 1 2 1 1 3 3 1 1 4 6 4 1

1 5 10 10 5 1 1 6 15 20 15 6 1 1 7 21 35 35 21 7 1 The Fibonacci numbers are

harder to locate. To find them you need to go up at an angle: you’re looking for

1, 1, 1+1, 1+2, 1+3+1, 1+4+3, 1+5+6+1 (Dr. Math, 4). Another thing I found out

is that if you multiply 11 x 11 you will get 121 which is the 2nd line in

Pascal’s Triangle. If you multiply 121 x 11 you get 1331 which is the 3rd line

in the triangle (Dr. Math, 4). If you then multiply 1331 x 11 you get 14641

which is the 4th line in Pascal’s Triangle, but if you then multiply 14641 x 11

you do not get the 5th line numbers. You get 161051. But after the 5th line it

doesn’t work anymore (Dr. Math, 4). Another example of probability: Say there

are four children Annie, Bob, Carlos, and Danny (A, B, C, D). The teacher wants

to choose two of them to hand out books; in how many ways can she choose a pair

(ladja, 4)? 1.A & B 2.A & C 3.A & D 4.B & C 5.B & D 6.C

& D There are six ways to make a choice of a pair. If the teacher wants to

send three students: 1.A, B, C 2.A, B, D 3.A, C, D 4.B, C, D If the teacher

wants to send a group of "K" children where "K" may range

from 0-4; in how many ways will she choose the children K=0 1 way (There is only

one way to send no children) K=1 4 ways ( A; B; C; D) K=2 6 ways (like above

with Annie, Bob, Carlos, Danny) K=3 4 ways (above with triplets) K=4 1 way

(there is only one way to send a group of four) The above numbers (1 4 6 4 1)

are the fourth row of numbers in Pascal Triangle (Ladja, 5). "If we extend

Pascal’s triangle to infinitely many rows, and reduce the scale of our picture

in half each time that we double the number of rows, then the resulting design

is called self-similar — that is, our picture can be reproduced by taking an

subtriangle and magnifying it," Granville notes.The pattern becomes more

evident if the numbers are put in cells and the cells colored according to

whether the number is 1 or 0 (Peterson’s, 5).Similar, though more complicated

designs appear if one replaces each number of the triangle with the remainder

after dividing that number by 3. So, I get: 1 1 1 1 2 1 1 0 0 1 1 1 0 1 1 1 2 1

1 2 1 1 0 0 2 0 0 1 This time, one would need three different colors to reveal

the patterns of triangles embedded in the array. One can also try other prime

numbers as the divisor (or modulus), again writing down only the remainders in

each position (Freedman, 5). Actually, there’s a simpler way to try this out.

With the help of Jonathan Borwein of Simon Fraser University in Burnaby, British

Columbia, and his colleagues, Granville has created a "Pascal’s Triangle

Interface" on the web. One can specify the number of rows (up to 100), the

modulus (from 2 to 16), and the image size to get a colorful rendering of the

requested form.It’s a neat way to explore the fractal side of Pascal’s triangle.

Here’s one example that I tried out, using 5 as the modulus (Petetson’s, 5)