140 likes | 330 Vues
This lesson explores the differences between exponential and linear functions through a detailed comparison using a table of values. Students will learn to identify linear behavior through constant differences in values, while exponential growth is indicated by constant ratios. The lesson includes step-by-step instructions for entering data into a calculator, determining formulas for each function, and comparing growth rates. By solving equations graphically or algebraically, students will understand how exponential growth eventually outpaces linear growth.
E N D
Comparing Exponential and Linear Functions Lesson 3.2
Table of Values • Use the data matrix of your calculator to enter the following values. • Column 1 is the x values • Columns 2 and 3 are the f(x) and g(x)
Table of Values • Click APPS then 6, then Current(F1, 8 to clear if needed) • Enter values as shown below
Two Different Functions • Note the succession of values for f(x) • Differ by 6 each • This implies linear
Cursor must be here Note ratio is 1.3 Two Different Functions • Note the succession of values for g(x) • They do NOT differ by a constant • However, the successive values have the same ratio • Show by placing formula in column 4 This shows it is an exponential function.
How to Determine the Formula • From previous lesson we know that • Where b is the growth factor • In our case the common ratio = 1.3 • Solve for a • Substitute b = 1.3, any ordered pair
Determine Function from Two Points • We can create twoequations with twounknowns • Solve for one of the variables • Substitute into the other equation • (-1, 2.5) (1, 1.6) • Answer b=0.8a=2
Lineary = m*x + by = m+m+ … m+ b x terms Exponentialy = a * bxy = a * b * b * … * b x factors Compare and Contrast
Compare and Contrast • Exponential growth will always outpace linear growth • In the long run • Eventually • Question:Where? • Solve graphically or algebraically or observe table
Where Exponential Passes Linear • Giveny = 100 (1.02)x y = 100 + 12x • Algebraically : no current tools to solve 100 (1.02)x = 100 + 12x • Graphically : ask calculator to find intersection • Or observe tables
Assignment • Lesson 3.2A • Page 119 • Exercises3, 5, 7, 9, 11, 13, 15, 17, 21, 23, 25 • Lesson 3.2B • Page 121 • Exercises27 – 39 odd