1 1 Patterns and Expressions Algebra 2 1

1 -1 Patterns and Expressions Algebra 2 1

Identifying Patterns can be represented using words, diagrams, numbers, or algebraic expressions. What is the next figure? Algebra 2 2

Look at the figures from right to left. What is the pattern? Algebra 2 3

Try this on your own. Draw the next figure. Algebra 2 4

Numerical Pattern What is the next number in the pattern 2, 4, 6, 8, …. 6, 3, 0, -3, …. Algebra 2 5

Variable- a symbol, usually a letter that represents one or more numbers ex: x or n Numerical Expression- mathematical phrase that contains numbers and operation symbols. ex: 3+5 Algebraic Expressions- mathematical phrase that contains one or more variables ex: 3 n+5 Algebra 2 6

Using Tables to help identify patterns Input Process Column Output 1 0 2 1 3 2 4 3 5 n Algebra 2 7

Input Process Column Output 1 5 2 9 3 13 4 17 5 n Algebra 2 8

Expressing a Pattern with Algebra How many toothpicks are in the 20 th figure? Figure Number (Input) Process Column Number of Toothpicks (output) 1 1(4) 4 2 2(4) 8 3 3(4) 12 n Algebra 2 9

Patterns on Graphs The graph shows the cost depending on the number of DVDs that you purchase. What is the cost of purchasing 5 DVD’s? 10 DVD’s? Input (x value) Process Column Output (y-value) 0 0 1 16 2 32 Algebra 2 10

Section 1 -1 Overview • Patterns- look at the figures or numbers from left to right and identify the pattern. • Variables are used in math to represent an unknown number in equations and inequalities. • Using Input/Output tables can help you find patterns. Algebra 2 11