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–3. 1. ANSWER. 27. 1. 2. 3. 5. 0. 2. –. –1. ANSWER. Evaluate the expression without using a calculator. –2. ANSWER. 10. 2. 3. 1.0075. ANSWER. Evaluate the expression without using a calculator. 3. 4 + 1.
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–3 1. ANSWER 27 1 2 3 5 0 2. – –1 ANSWER Evaluate the expression without using a calculator.
–2 ANSWER 10 2 3 1.0075 ANSWER Evaluate the expression without using a calculator. 3. 4 + 1 4.A savings account pays 3% interest compounded monthly. What is the growth factor for this account?
x Graph y = x 1 Graph y = b for 0 < b < 1 2 EXAMPLE 1 SOLUTION STEP 1 Make a table of values STEP 2 Plot the points from the table. STEP 3 Draw, from right to left, a smooth curve that begins just above the x-axis, passes through the plotted points, and moves up to the left.
a. Graphy = 2 x Graph y = ab for 0 < b < 1 x a. Plot (0, 2) and .Then, from right to left, draw a curve that begins just above the x-axis, passes through the two points, and moves up to the left. 1 1 4 2 1, EXAMPLE 2 Graph the function. SOLUTION
1,– x Graph y = ab for 0 < b < 1 x b. Graphy = –3 2 6 b. 5 5 Plot (0, –3) and . Then,from right to left, draw a curve that begins just below the x-axis, passes through the two points,and moves down to the left. EXAMPLE 2 Graph the function. SOLUTION
x 2 3 1. y = for Examples 1 and 2 GUIDED PRACTICE Graph the function.
x 2. y = –2 3 4 for Examples 1 and 2 GUIDED PRACTICE Graph the function.
1 5 x 3. f(x) = 4 for Examples 1 and 2 GUIDED PRACTICE Graph the function.
Begin by sketching the graph of y = , which passes through (0, 3) and . Then translate the graph left 1 unit and down 2 units .Notice that the translated graph passes through (– 1, 1) and Graph y = 3 –2. State the domain and range. x – h 1 – 1 1 3 Graph y = ab + k for 0 < b < 1 2 2 2 2 x 3 0, x+1 1, EXAMPLE 3 SOLUTION
x – h Graph y = ab + k for 0 < b < 1 EXAMPLE 3 The graph’s asymptote is the line y = –2. The domain is all real numbers, and the range is y > –2.
Snowmobiles A new snowmobile costs $4200. The value of the snowmobile decreases by 10% each year. EXAMPLE 4 Solve a multi-step problem • Write an exponential decay model giving the snowmobile’s value y (in dollars) after t years. Estimate the value after 3 years. • Graph the model. • Use the graph to estimate when the value of the snowmobile will be $2500.
t y = a(1 –r) t = 4200(1 –0.10) t = 4200(0.90) When t = 3, the snowmobile’s value is y = 4200(0.90)3 = $3061.80. EXAMPLE 4 Solve a multi-step problem SOLUTION STEP 1 The initial amount is a= 4200 and the percent decrease is r = 0.10. So, the exponential decay model is: Write exponential decay model. Substitute 4200 for aand 0.10 for r. Simplify.
EXAMPLE 4 Solve a multi-step problem STEP 2 The graph passes through the points (0, 4200) and (1, 3780).It has the t-axis as an asymptote. Plot a few other points. Then draw a smooth curve through the points. STEP 3 Using the graph, you can estimate that the value of the snowmobile will be $2500 after about 5 years.
x–1 4.y = +1 1 4 for Examples 3 and 4 GUIDED PRACTICE Graph the function. State the domain and range.
x+1 2 5. y = 5 –2 3 for Examples 3 and 4 GUIDED PRACTICE Graph the function. State the domain and range.
3 4 x – 5 6. g(x) = –3 +4 for Examples 3 and 4 GUIDED PRACTICE Graph the function. State the domain and range.
SOLUTION y = 4200(0.8)tAfter about 2 yr. for Examples 3 and 4 GUIDED PRACTICE 7.WHAT IF?In Example 4, suppose the value of the snowmobile decreases by 20% each year. Write and graph an equation to model this situation. Use the graph to estimate when the value of the snowmobile will be $2500.
SOLUTION $3729.69 for Examples 3 and 4 GUIDED PRACTICE 8. SNOWMOBILE The value of a snowmobile has been decreasing by 7% each year since it was new. After 3 years, the value is $3000. Find the original cost of the snowmobile.
x 1. Graphy = 4 .State the domain and range. ANSWER 1 2 domain: all real numbers range:y > 0 Daily Homework Quiz
x+2 2. Graphy = 3 +2 .State the domain and range. ANSWER 1 4 domain: all real numbers range:y > 2 Daily Homework Quiz
about $ 913 ANSWER after about 4 yr ANSWER Daily Homework Quiz 3. A new laptop computer costs $1500. The value of the computer decreases by 22% each other. a. Estimate the value of the computer after 2 years. b.Estimate when the computer will be worth $550.