1 While searching for a fun and interesting lesson to start the school year, I ran across several activities that relate to Pascal’s Triangle. I know that students are often intimidated to start the first day of school with heavy-duty math concepts, so this array of numbers seemed like a great place to start. The activity I chose to use allowed students to work in groups to discover several elementary patterns. I know that students tend to get excited when they make discoveries so I thought it would be fun way to get started. Beginning the year with a lesson on Pascal’s Triangle allowed me to build upon seemingly simple patterns throughout the year. I have always found Pascal’s Arithmetic Triangle to be fascinating. I was aware of several useful applications that turn up in typical high school math textbooks. Through my research I found a number of applications that I was unaware of. What the reader will find in this paper is a collection of interesting patterns and useful applications of Pascal’s Triangle. The number of patterns is countless, so this paper is just the tip of the iceberg. Also included are some student worksheets that can be used in a middle school or high school classroom. Each worksheet will lead to discoveries by students which will allow them to build on previous knowledge. 2 Figure 1: Pascal’s Triangle (Green, 1986) Pascal’s Arithmetic Triangle is a triangular array of whole numbers. It is also known as the figurate triangle, the combinatorial triangle, and the binomial triangle. The top of the triangle always starts with the number 1. Numbers in a horizontal line make up a row. The first and last numbers in each row are 1. Each of the other numbers in a row is found by adding the two numbers above it. It is generally understood that the top row, which contains a single number 1, is row 0. This is because it corresponds to the expansion of . Binomial expansion will be discussed later in this paper. The rows continue to be counted 3 row 1, row 2, row 3, etc. There are an infinite number of rows because the triangle itself is infinite. Numbers in an oblique line on the diagonal are called diagonals. Figure 2: Rows and Diagonals (Seymour, 1985) A number in Pascal’s Triangle is referred to as an element. The number of elements is always one more than the number of the row. For example, there are 5 elements row 4. The number of elements in a diagonal is infinite because the diagonal never ends. Figure 3: Elements (Seymour, 3) Although Pascal’s Triangle is named after 17th century mathematician Blaise Pascal, many other mathematicians knew about and used their knowledge of this array hundreds of years before the birth of Pascal. There is some proof that this number triangle was familiar to the Arab astronomer and mathematician 4 Omar Khayyam as early as the 11th century.1 Some historians believe that the numbers originally arose from the Hindu study of combinatorics and binomial numbers as well as the Greeks study of figurate numbers.2 The numbers appear to have been discovered independently by both Persian and Chinese mathematicians in the 11th century.3 In 1261, Yang Hui listed the numbers up to row 6. He called the triangle “the tabulation system for unlocking binomial coefficients.” The same triangle extended to row 8 was given by Chu Shih-Chieh in 1303.4 The Chinese began calling the numbers “Yanghui’s Triangle” because Chu Shih-Chieh gave credit to Yanghui who worked with the triangle 40 years prior.5 Most likely the triangle came to Europe from China through Arabia.6 In Europe, there are many authors who can lay claim to having made a serious study of the triangle. Several of them studied the triangle long before Pascal was even born.7 In some Italian works, the array is called “Tartaglia’s Triangle” named after Italian algebraist Tartaglia who published the numbers in 1556.8 Other mathematicians who worked on the triangle are Gerolamo Cardano in 1 Jessica Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html> 2 “Pascal’s Triangle-History in Europe.” Pascal’s Triangle From Top to Bottom. 4 Oct. 2008 <https://www.math.ucon.edu/~troby/hidden/4math/ptw/europe.html>. 3 Jessica Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html> 4 A.W.F Edwards, Pascal’s Arithmetical Triangle. (London: Charles Griffin & Company LTD, 1987) 51. 5 “Pascal’s Triangle-History in Europe.” Pascal’s Triangle From Top to Bottom. 4 Oct. 2008 <https://www.math.ucon.edu/~troby/hidden/4math/ptw/europe.html>. 6 “Pascal Triangle – History” Fibonacci Numbers and the Pascal Triangle. 4 Oct. 2008 <http://milan.milanovic.org/math/english/fibo/fibo0.html> 7 “Pascal’s Triangle-History in Europe.” Pascal’s Triangle From Top to Bottom. 4 Oct. 2008 <https://www.math.ucon.edu/~troby/hidden/4math/ptw/europe.html>. 8 Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html> 5 1539, Francois Viete in 1591, William Oughtred in 1631, Henry Briggs in 1633 and Father Marin Mersenne in 1663.9 The numbers were published many times in countries around the world before Pascal, but he did a lot of the original work. He also discovered many identities in the numbers.10 Blaise Pascal (1623-1662) was part of a generation of great mathematicians in France that include Decartes, Fermat and Father Marin Mersenne.11 Pascal invented a calculating machine, worked on the barometer and produced work on conic sections.12 Pascal and his father, Etinne, came in contact with Father Marin Mersenne who published a book with a table of binomial coefficients in 1636.13 Pascal also entered into correspondence with Pierre de Fermat in 1654. This correspondence was in regard to a problem in calculating the odds in games of chance. This problem, the Gambler’s Problem of Points, concerned the division of the stakes between two players when a game has to be left unfinished. This 9 Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html> 10 “Pascal Triangle – History” Fibonacci Numbers and the Pascal Triangle. 4 Oct. 2008 <http://milan.milanovic.org/math/english/fibo/fibo0.html> 11 “Pascal’s Triangle-History in Europe.” Pascal’s Triangle From Top to Bottom. 4 Oct. 2008 <https://www.math.ucon.edu/~troby/hidden/4math/ptw/europe.html>. 12 Tony Colledge, Pascal’s Triangle: A Teacher’s Guide with Blackline Masters (Minneapolis: Tarquin Publications, 1997) 2. 13 “Pascal Triangle – History” Fibonacci Numbers and the Pascal Triangle. 4 Oct. 2008 <http://milan.milanovic.org/math/english/fibo/fibo0.html> 6 correspondence resulted in Pascal’s most famous publication, “Traite du Triangle Arithmetique,” probably in August of 1654.14 In his publication, Pascal explained how the figurate numbers were in fact both the combinatorial numbers and the binomial numbers. He also developed many of the triangles properties and applications within these writings. Pascal was not the first man in Europe to study the binomial coefficients. However, Pascal’s contributions to math, especially of his triangle were unquestionably brought forth from the mind of a highly intelligent man.15 It is considered bad form to name something after yourself. Mathematicians name things by giving credit the author of a paper after the fact. Monmort, writing in French in 1708 called this array of numbers the “combinatorial table of Mr. Pascal”.16 Pascal’s extensive work on probability theory is what caused the triangle to be named after him.17 Pascal’s Triangle contains several amazing and interesting patterns. Its applications are incredible, as well. One of the first mysteries to be spotted is that the numbers of the array are symmetric. A line drawn vertically through the center of the triangle creates mirror images as seen in Figure 4. 14 “Pascal Triangle – History” Fibonacci Numbers and the Pascal Triangle. 4 Oct. 2008 <http://milan.milanovic.org/math/english/fibo/fibo0.html> 15 Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html> 16 Pascal’s Triangle-History in Europe.” Pascal’s Triangle From Top to Bottom. 4 Oct. 2008 <https://www.math.ucon.edu/~troby/hidden/4math/ptw/europe.html>. 17 Tony Colledge, Pascal’s Triangle: A Teacher’s Guide with Blackline Masters (Minneapolis: Tarquin Publications, 1997) 2. 7 Figure 4: Symmetry in Pascal’s Triangle (Seymour, 2) There are also patterns found in the diagonals of Pascal’s Triangle. To begin, diagonal 0 is full of 1s. Diagonal 1 is the sequence of counting numbers. Diagonal 2 is the set of triangular numbers. The successive triangular numbers are where term and . So, stands for the .18 In simpler terms, the triangular numbers are 1, and and so on, as pictured in Figure 5. Figure 5: The first 4 triangular numbers (Edwards, 2) Adding any two successive numbers in diagonal 2 results in a perfect square. A square number, , can be pictured as rows of dots and is equal to (see Figure 6). In other words, the third perfect square, 9, can be pictured as a square consisting of 3 rows of 3 dots. Also, 18 19 A.W.F. Edwards Pascal’s Arithmetical Triangle. (London: Charles Griffin & Company LTD, 1987) 1. 19 A.W.F. Edwards Pascal’s Arithmetical Triangle. (London: Charles Griffin & Company LTD, 1987) 1. 8 Figure 6: The first 4 square numbers (Edwards, 2) The set of tetrahedral numbers (1, 4, 10, 20 …) is given in diagonal 3. Tetrahedral numbers are the sum of the triangular numbers (1, 1 6, 1 4 6 3, 1 3 10 .20 In Figure 7, the numbers located on each of the drawn-in diagonals of Pascal’s Triangle sum to the Fibonacci sequence.21 Recall that Fibonacci’s sequence begins with two 1s and then all other numbers are generated by summing the two numbers before the next term in the sequence (1, 1, 1 1 2 3, 12 3 1 2, 5 . Figure 7: Fibonacci’s sequence in Pascal’s Triangle (Green, 78). The horizontal rows represent powers of 11. Row 0 is 11 11 20 11 (1, 1). Row 2 is 11 1. Row 1 is 121 (1, 2, 1). Jessica Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html> 21 Thomas Green. Pascal’s Triangle. (Minneapolis: Dale Seymour Publications, 1986) 78. 9 Add the numbers in each row of Pascal’s Triangle. What pattern is found in the results? Adding rows shows a pattern of doubling. The sums are powers of 2. The sum of the elements in row 3 is 1 1 4 6 4 1 16 3 3 1 8 2 . In row 4, 2 . For any prime numbered row, or row where the first element is a prime number, all of the numbers in that row (excluding the 1s) are divisible by that prime. In mathematical terms it can be stated that “if is a prime number, then all the middle elements (all elements except the two end elements) of the row are divisible by ”.22 For example, row 7 consists of the numbers 1, 7, 21, 35, 35, 21, 7, and 1. Besides the 1s that begin and end the row, all of the numbers are divisible by 7. On the other hand, if is a composite number then some elements in the row will be divisible by . Another pattern found in Pascal’s Triangle is called the Hockey Stick pattern. Sum the first four elements of diagonal 2: 1 3 6 10 20. Outlining these numbers and the resulting sum creates a figure that is shaped like a hockey stick as shown in Figure 8. The same can be seen when you add the first five elements of diagonal 2. The diagonal of numbers of any length starting with any of the 1s bordering the side of the triangle and ending on any element inside the triangle is equal to the number below the last element of the 22 Jessica Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html> 10 diagonal not on the diagonal.23 This is true because 1 1 as proved in Appendix A. Because of the symmetry in Pascal’s Triangle that was discussed earlier, the hockey stick pattern can be formed in either direction.24 Figure 8: Hockey Stick Pattern (Green, 53). Another interesting pattern that emerges is in the products of rings in Pascal’s Triangle. When you multiply the numbers in a ring, the product is always a perfect square number. 25 Take one of the examples in Figure 9. 23 Jessica Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html> 24 Thomas Green. Pascal’s Triangle (Minneapolis: Dale Seymour Publications, 1986) 53. Dale Seymour. Visual Patterns in Pascal’s Triangle. (Minneapolish: Dale Seymour Publications, 1985) 45 25 11 Figure 9: Rings in Pascal’s Triangle (Seymour, 45). Multiplying the elements in the ring with 3 as a center results in 1 4 1 144 2 3 6 12 . Also, in the ring with 84 as it’s center, we will multiply 56, 28, 36,120, 210, and 126. 56 2 · 7 28 2 · 7 36 2 · 3 120 2 · 3 · 5 210 2 · 3 · 5 · 7 126 2 · 3 · 7 So, 56 · 28 · 36 · 120 · 210 · 126 2 ·3 ·5 ·7 Since this result has all even powers, it is a perfect square! A student activity and worksheet, Exploring Patterns, is provided in Appendix B. Some of the most interesting patterns are visual patterns that can be seen when the elements of the triangle are colored. For example, when the even numbers are colored a different color than the odd numbers, the result is a 12 pattern that is the same as the Sierpinski Triangle (see Figure 10). This triangle is a fractal named after Wacław Sierpiński who described it in 1915.26 The pattern shows stepped triangles. Figure 10: Evens and Odds (Seymour, 19) What’s even more interesting is that this fractal does not only show up when evens (multiples of 2) are colored. Generating the pattern made by coloring the multiples of other numbers is an extension of the work on odd and even numbers. A pattern that is eerily similar to the Sierpinski triangle emerges when multiples of 3, 4, 5, 6, 7, 8, 9, and 10 are colored as shown in Figure 11. Figure 11: Multiples of 3, 4 and 7 (Seymour, 19). A student activity worksheet, Coloring Multiples, is included in Appendix C. 26 “Applicaions of Pascal’s Triangle.” Learn Something New Every Day. 4 Oct. 2008 <http://mihirknows.blogspot.com/2007/10/applications-of-pascals-triangle.html> 13 While the patterns described above are fun and interesting, there are many aspects of Pascal’s Triangle that are applicable to middle and high school math. One of these applications is probability. The State of Ohio Board of Education lists Probability as one of its Academic Content Standards. A grade level indicator for the eighth grade states that students should be able to: “Calculate the number of possible outcomes for a situation, recognizing and accounting for when items may occur more than once or when order is important”.27 A grade level indicator for the ninth grade states that students should: “Use counting techniques and the Fundamental Counting Principle to determine the total number of possible outcomes for mathematical situations”.28 Pascal’s Triangle can be used to allow students to demonstrate knowledge in both of these areas. It shows you the results of heads and tails when a fair, 2-sided coin is tossed.29 For example, let us say that a fair, 2-sided coin is tossed three times. What is the probability that the three tosses will result in 2 heads and 1 tail? There is only 1 way that the tosses will result in three heads. There are 3 ways that two heads and one tail can be tossed. There are also 3 ways that one head and two tails can be tossed. And finally, there is only 1 way that three tails can be tossed. Now, look at row 3 of the triangle. The elements, 1, 3, 3, 1 give us the number of times each result can occur. So, it is 27 Ohio Department of Education, comp. Academic Content Standards: K-12 Mathematics. (Columbus, OH: State of Ohio Bard of Education, 2001) 105 28 Ohio Department of Education, comp. Academic Content Standards: K-12 Mathematics. (Columbus, OH: State of Ohio Bard of Education, 2001) 105 29 “Applicaions of Pascal’s Triangle.” Learn Something New Every Day. 4 Oct. 2008 <http://mihirknows.blogspot.com/2007/10/applications-of-pascals-triangle.html> 14 easy to see that there is a 3 out of 8 chance that tossing three coins will result in 2 heads and 1 tail. (See Coin Tossing Activity: Appendix D and Investigation: Appendix E). Pascal’s Triangle can also be used to teach middle and high school students about combinations.30 The elements of Pascal’s Triangle can be used to find out how many subsets of elements can be formed from a set with distinct elements.31 For example, let us say that we must choose three videos from a box of seven. In how many different ways can we chose the videos? The ! solution can be found using the combination rule 7 and 3. So, 7 3 ! ! ! ! · · · · · · ! ! · · · · · · , where in this case ! ! 35. Pascal’s Triangle saves the trouble of using this tedious formula. Since we are choosing three elements from seven, we will find the 3rd element in row 7. Row 7 consists of the elements 1, 7, 21, 35, 35, 21, 7, 1. Remember that the first 1 is element 0. So, the 3rd element is 35. This means in the formula equal to the row number of the triangle where , is is equal to the element in that particular row.32 (See Appendix F: Pizza Problem). As one familiar with Algebra may know, the numbers in each row of the triangle are precisely the same numbers that are the coefficients of binomial 30 Prentice Hall, comp. Middle Grades Math: Tools for Success. (Upper Saddle River, New Jersey: Prentice Hall, 1999) 553 31 Jessica Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/ 32 Jessica Kazimir, Pascal’s Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/ 15 expansions.33 The Ohio State Board of Education indicates that students in the twelfth grade should be able to: “Apply combinations as a method to create coefficients for the Binomial Theorem, and make connects to everyday and workplace problem situations”.34 Consider the expansion of . To simplify, one may multiply . The result is variables are all combinations of and 4 6 4 . The where the sums of the exponents are equal to four. In other words, the degree of each term is four. The coefficients of the terms (1, 4, 6, 4, 1) correspond exactly to the numbers in row 4 of Pascal’s Triangle. So, in general, the th row of the triangle gives the expansion coefficients of . This is proved in Appendix G. A direct expansion for each coefficient is … … . This is the same formula for finding combinations, as discussed previously. So, the coefficients of any binomial expansion can be found by finding where the upper index, , is the exponent for the first variable and the lower index, , is the term.35 (See Appendix H: Binomial Coefficients). The patterns that can be found in Pascal’s Triangle are endless, so the patterns discussed in this paper are just the beginning. Its applications abound. Young students can use the triangle to find and explore patterns. High school 33 “Applicaions of Pascal’s Triangle.” Learn Something New Every Day. 4 Oct. 2008 <http://mihirknows.blogspot.com/2007/10/applications-of-pascals-triangle.html> 34 Ohio Department of Education, comp. Academic Content Standards: K-12 Mathematics. (Columbus, OH: State of Ohio Bard of Education, 2001) 185 35 “Binomial Theorem-Topics in Precalculus.” The Math Page: Topics in Precalculus. 4 Oct. 2008 <http://www.themathpage.com/aprecalc/binomial-theorem.htm> 16 students can use the triangle to complete complicated computations and increase their knowledge of binomial expansions. From elementary to complex, Pascal’s Triangle can be used to teach and explore many mathematical subjects. 17 Appendix A Proof: 1 1 ! ! 1 ! ! 1 ! ! ! 1 ! ! ! 1 1 ! ! ! 1 1 ! ! · ! 1 ! ! ! 1 ! 1 ! ! 1 1 ! ! 1 ! 1 ! 1 ! · ! 1 ! ! ! · ! 1 ! ! 1 1 ! ! 1 ! ! 4 1 4 1 ! ! 1 ! 1 1 ! ! 18 Appendix B Pattern Exploration Directions: Use a copy of Pascal’s Triangle showing the first 9 rows to answer the following questions about your general exploration: 1). List any pattern that you find. ______________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ 2). Predict the next row of numbers and write them here. 3). Explore the pattern in the sums of the numbers for each row 1-9? Describe that pattern here: _____________________________________ ___________________________________________________________ 4). • Find the following sets of numbers embedded in the triangle. Describe where you found them. Natural numbers {1, 2, 3, 4, …} _________________________________ ___________________________________________________________ • Powers of 2 {1, 2, 4, 8, …} _____________________________________ ___________________________________________________________ • Triangular numbers {1, 3, 6, 10, …} ______________________________ ___________________________________________________________ • Fibonacci numbers {1, 1, 2, 3, 5, 8, …} ____________________________ ___________________________________________________________ 19 Appendix C Coloring Multiples Exploration Questions Pascal's Triangle is very interesting from a number pattern point of view. 1. Color all of the odd numbers one color and all of the even numbers another on your copy of Pascal's Triangle. What do you notice about the pattern? Have you seen it before? 2. Use another copy of Pascal’s Triangle to explore other patterns. Try at least three different multiples. Do you see a general pattern? Describe how each number you try relates to the pattern for that number. 20 Coin Tossing Activity Appendix D Introduction: Coin flipping is based on probability. With an fair coin, the chances of winning or losing are 50% and consequently, coin flipping is used to decide such momentous events like who kicks off in a football game. We often used the terms “it’s a coin toss” or “flip a coin” to describe events that are random with an equal chance of happening. In this activity students will investigate coin tossing as it relates to scientific data collection. According to the Pascal triangle, if you toss 6 coins, you can get one of 7 possibilities with the percent probability of each listed: Possibility #1 #2 #3 #4 #5 #6 #7 Outcome 0 heads, 6 tails 1 head, 5 tails 2 heads, 4 tails 3 heads, 3 tails 4 heads, 2 tails 5 heads, 1 tail 6 heads, 0 tails Occurrence (64 tosses) 1 6 15 20 15 6 1 Percent 1.6% 9.4% 23.4% 31.3% 23.4% 9.4% 1.6% Based on the laws of probability and with fair coins, students should obtain the above outcomes. But the factor of random error will influence the results just as it does in scientific data gathering. Even so, it is obvious that it is very unlikely one would get 6 heads or 6 tails in a row. Procedure: The class will break into teams of two or three. Each team will have a box and lid with 6 pennies, and will do 64 trials. They will record their results. At the end of the 64 trials, complete a table by totaling each outcome. Calculate the percent you obtained for each possibility. • • • Make a histogram of the results and compare it with the mathematically predicted results. Use Excel or a graphing calculator. How well did your coin flipping agree with Pascal’s triangle? Now compare results with other teams. How well did other teams do? List the occurrences of each team on the board. Does random error affect the expected results? To overcome the random error, scientists like to take lots of data. When this is done, it is hoped that the biases over a short run will cancel each other out. To see this, combine each of the students’ groups into one large group. • • Does this grand sum more closely approach the expected occurrences predicted in the Pascal triangle? Can you see why this is so? 21 Coin Flipping Activity Worksheet Answer these questions based on your team and the class’s results. Give a reason for your answers. 1. How well did your coin flipping agree with the theoretical results of Pascal’s Triangle? 2. How well did other teams’ coin flipping agree with the theoretical results of Pascal’s Triangle? What experimental factor accounts for the results? 3. How well did grand sum of all the teams agree with the theoretical results of Pascal’s Triangle? 4. Give a reason why you would expect the grand sum to be closer to the theoretical percentage. 5. Why do scientists like to take large data sets rather than small ones? 6. Are there any disadvantages to taking large data sets? 22 Tossing Multiple Coins Appendix E Complete the table by listing the possible outcomes. Example: If you toss 2 coins, the possible outcomes are {HH, HT, TH, TT}. 1 coin 0 Tails 1 Tail 2 coins 0 Tails HH 1 Tail 2 Tails HT TH TT 3 coins 0 Tails 1 Tail 2 Tails 3 Tails 4 coins 0 Tails 1 Tail 2 Tails 3 Tails 4 Tails 5 coins 0 Tails 1 Tail 2 Tails 3 Tails 4 Tails 5 Tails 23 Appendix F Pizza Problem It's pizza night for the Shattuck family! Alli heads to LaRosa’s to pick up a large pizza. However, when she gets there she realizes she didn't check with the family as to toppings. Rather than imposing her own preferences (pepperoni – no anchovies!), she decides to call home and ask. The pizza parlor offers 8 different toppings: anchovies, extra cheese, green peppers, mushrooms, olives, pepperoni, sausage, and onions. How many different pizzas could Alli order if a pizza could be selected with any combination of toppings? Use the following to help you organize your lists. 1) How many different pizzas could Alli order with only one topping? _____ 2) How many different pizzas can she order each with seven toppings? _____ 3) Are the number of one-topping pizzas and the number of seven-topping pizzas related? Why or why not? ________________________________ 4) How many different pizzas can Alli order with two toppings? _________ 5) How many different pizzas can she order with six toppings? ___________ 6) Are the number of two-topping pizzas and the number of six-topping pizzas related? Why or why not? ________________________________ 7) Find these numbers in Pascal's Triangle. 8) Use Pascal's Triangle to help you find the number of pizzas that Alli could order with three, four, and five toppings. ___________________________ 9) Now… How many different pizzas could Alli order if a pizza could be selected with any combination of toppings?_________________________ 24 10) Can you see another way to approach this problem? What if instead of figuring out how many pizza topping combinations were possible, Alli stood and answered the following questions? • • • • • • • • Do you want anchovies? Do you want extra cheese? Do you want green peppers? Do you want mushrooms? Do you want olives? Do you want pepperoni? Do you want sausage? Do you want onions? How could this information help Alli find all the different ways a pizza could be ordered? Describe. ________________________________________________ ________________________________________________________________ 25 Appendix G ∑ Proof: by induction Let 1; then Let ; then 1 0 0 1 1 1 1 1 1 1 1 1; then Let 1 1 + 1 1 1 1 … 1 … 1 + 1 1 1 0 0 1 1 1 0 1 1 1 0 ∑ 1 1 1 1 26 Binomial Coefficients Appendix H Problem: Consider 1 . Multiply it out by considering all possible ways to “thread through” the factors. • How many summands are there before you can add like terms? _____ • How many summands will be of the form “ ”? _______ • How many summands will be of the form “ ”? _______ • How many summands will be of the form “ ”? _______ Express the polynomial in standard form: _______________________________ • Determine the coefficients where ∑ _____ • ______ _______ _______ ______ How do these coefficients relate to Pascal’s Triangle? ____________ ________________________________________________________ Little Binomial Theorem: Let Binomial Theorem: Let be a whole number. Then, be a whole number. Then, 1 ________ ____________ Use the Binomial Theorem to expand each of the following. 1. 5 _______________________________________________________________ 2. 1 ________________________________________________________________ 3. ________________________________________________________________ 4. 3 _____________________________________________________________ 27 Works Cited "Applications of Pascal's Triangle." Learn Something New Every Day. 4 Oct. 2008 <http://mihirknows.blogspot.com/2007/10/applications-of-pascalstriangle.html>. "Binomial Theorem - Topics in Precalculus." The Math Page: Topics in Precalculus. 4 Oct. 2008 <http://www.themathpage.com/aprecalc/binomial-theorem.htm>. "Blaise Pascal (1625-1662)." Blaise Pascal (1625-1662). 4 Oct. 2008 <http://www.maths.tcd.ie/pub/histmath/people/pascal/rouseball/rb_pascal. html>. "Chinese Mathematics." Binomial Theorem and the Pascal Triangle. 4 Oct. 2008 <http://roma.unisa.edu.au/07305/pascal.htm>. Colledge, Tony. Pascal's Triangle : A Teacher's Guide with Blackline Masters. Minneapolis: Tarquin Publications, 1997. Edwards, A.W.F. Pascal's Arithmetical Triangle. London: Charles Griffin & Company LTD, 1987. Epp, Susanna S. Discrete Mathematics with Applications. Pacific Grove: Brooks/Cole Company. Green, Thomas. Pascal's Triangle. Minneapolis: Dale Seymour Publications, 1986. "Inventor Blaise pascal Biography." The Great Idea Finder. 4 Oct. 2008 <http://www.ideafinder.com/history/inventors/pascal.htm>. 28 Kazimir, Jessica, Pascal's Triangle. 4 Oct. 2008 <http://pages.csam.montclair.edu/~kazimir/index.html>. Larson, Kanold, Stiff. Algebra 2: An integrated Approach. Lexington, MA: DC Heath and Company, 1995. Ohio Department of Education, comp. Academic Content Standards: K-12 Mathematics. Columbus, OH: State of Ohio Board of Education, 2001. "Pascal Triangle-History." Fibonacci Numbers and the Pascal Triangle. 4 Oct. 2008 <http://milan.milanovic.org/math/english/fibo/fibo0.html>. "Pascal's Triangle - History in Europe." Pascal's Triangle From Top to Bottom. 4 Oct. 2008 <http://www.math.ucon.edu/~troby/hidden/4math/ptw/europe.html>. "Pascal's Triangle and the Fibonacci Series." GoldenNumber.net. PhiPoint Solutions, LLC. 4 Oct. 2008 <http://goldennumber.net/pascal.htm>. "Pascal's Arithmetic Triangle." The Math Forum at Drexel. Drexel University. 4 Oct. 2008 <http://forum.swarthmore.edu>. Prentice Hall, comp. Middle Grades Math: Tools for Success. Upper Saddle River, New Jersey: Prentice Hall, 1999. “Science Encyclopedia”, Pascal's Triangle-History 10 March 2009 <http://science.jrank.org/pages/5061/Pascal-s-Triangle-Pascal.html >. Seymour, Dale. Visual Patterns in Pascal's Triangle. Minneapolis: Dale Seymour Publications, 1985.