Chapter 4 – Graphing Linear Equations and Functions Algebra I A - Meeting 23 Example # 1 Step 1 : Make a Input-Output Table: Step 2 : List & Plot the Ordered Pairs(Points) Graph the equation xy = -x-1y y =-(-1)-1 = y =-(0)-1 = y =-(1)-1 = y =-(2)-1 = y =-(3)-1 = Section 4.2 – Graph Linear Equations Domain: -1 ≤ x ≤ 3.Identify the range of the function. Step 3: Graph the Function, use the ordered pairs Step 4: Identify the range. -4 ≤ y ≤ 0

Chapter 4 – Graphing Linear Equations and Functions Algebra I A - Meeting 23 Example # 2 Step 1 : Identify the domain or range: Step 2 : Make a Input-Output Table The number of pages a student types is given by p = 4t, where t is the time (in hours) spent typing. The student plans to type for at most 2.5 hours. Graph the function and identify its domain and range. tp = 4 tp 0p = 4 (0)0 0.5p = 4 (0.5)2 1p = 4 (1)4 1.5p = 4 (1.5)6 2p = 4 (2)8 2.5p = 4 (2.5)10 Section 4.2 – Graph Linear Equations Step 4: Graph the Function, use the ordered pairs Step 3: List the Ordered Pairs. 0 ≤ y ≤ 10 Domain : 0 ≤ t ≤ 2.5 Step 5: Identify the range :

Chapter 4 – Graphing Linear Equations and Functions Algebra I A - Meeting 23 Example # 3 Step 1 : Identify the domain or range: Step 2 : Make a Input-Output Table Suppose in the previous example, the student plans to type at most 14 pages. Graph the function and identify its domain and range. tp = 4 tp 0(0) = 4 t0 0.5(2) = 4 t2 1(4) = 4 t4 1.5(6) = 4 t6 2(8) = 4 t8 2.5(10) = 4 t10 3(12) = 4 t12 3.5(14) = 4 t14 Section 4.2 – Graph Linear Equations Step 5: Graph the Function, use the ordered pairs Step 4: List the Ordered Pairs. 0 ≤ t ≤ 3.5 Range : 0 ≤ p ≤ 14 Step 3: Identify the Domain :

Chapter 4 – Graphing Linear Equations and Functions Algebra I A - Meeting 23 X – Intercept – is the x - coordinate of a point where the graph crosses the x-axis. (a,0) Section 4.3 – Graph Using Intercepts Y – Intercept – is the y - coordinate of a point where the graph crosses the y-axis. (0,b) Example # 4 Find the x-intercept and the y-intercept of the graph of 3x – 4y = 12 Write the Original Equation. Step 1: Find the x-intercept: Substitute 0 for y and solve for x. Substitute 0 for y. Simplify Divide each side by 3. Simplify The x – intercept is 4. Write the Original Equation. Step 2: Find the y-intercept: Substitute 0 for x and solve for y. Substitute 0 for x. Simplify Divide each side by -4. Simplify The x – intercept is graphed at The y – intercept is -3. The y – intercept is graphed at

Chapter 4 – Graphing Linear Equations and Functions Algebra I A - Meeting 23 Section 4.3 – Graph Using Intercepts Example # 4 (con’t) - Use the x-intercept and the y-intercept as the critical points of the line. Step 3: Graph the function: The x – intercept is 4. The x – intercept is graphed at The y – intercept is -3. The y – intercept is graphed at

Chapter 4 – Graphing Linear Equations and Functions Algebra I A - Meeting 23 Example # 5 Section 4.3 – Graph Using Intercepts The Freshman Class makes and sells decorative bows. They sell small bows for $3 and large bows for $5. They want to earn $60 per week. Find the intercepts, Graph the equation and Give the possible combinations of the # of each bow that can be sold, for the Freshman class to earn $60. You can model situation by the equation: 3x +5y = 60 where x is the number of small bows and y is the number of large bows. Step 1: Find the x-intercept and the y-intercept for 3x +5y = 60. Write the Original Equation. Find the x-intercept: Substitute 0 for y. Simplify Divide each side by 3. Simplify The x – intercept is 20. Write the Original Equation. Find the y-intercept: Substitute 0 for x. Simplify Divide each side by. Simplify The x – intercept is graphed at The y – intercept is 12. The y – intercept is graphed at

Chapter 4 – Graphing Linear Equations and Functions Algebra I A - Meeting 23 Section 4.3 – Graph Using Intercepts Example # 5 (con’t) - Use the x-intercept and the y-intercept as the critical points of the line. Step 3: Graph the equation: The x – intercept is 20. The x – intercept is graphed at The y – intercept is 12. The y – intercept is graphed at Step 4 : Select Possible Combinations for Small and Large Bows sold to earn $ Small Bows & 0 Large Bows 0 Small Bows & 12 Large Bows 10 Small Bows & 6 Large Bows 15 Small Bows & 3 Large Bows

Chapter 4 – Graphing Linear Equations and Functions Algebra I A - Meeting 23 Homework # 16 pg 220 # 35 – 37 all pg 229 # 3 – 30 mults. of 3; # 45 Section 4.2, 4.3