Math Problem Statement

Determine the slope of the secant line of f for each of the intervals indicated in the table

Determine the slope of the secant line of f for each of the intervals indicated in the table for the function f(x) = 2x^2 - 12x + 10.

Solution

We are asked to find the slope of the secant line for the function f(x)=2x212x+10f(x) = 2x^2 - 12x + 10 over the interval [4,x2][4, x_2] for various values of x2x_2 as indicated in the table.

The formula for the slope of the secant line between two points x1x_1 and x2x_2 on the function f(x)f(x) is given by:

Secant Slope=f(x2)f(x1)x2x1\text{Secant Slope} = \frac{f(x_2) - f(x_1)}{x_2 - x_1}

In this case, x1=4x_1 = 4 and we will calculate the secant slope for each x2x_2 given in the table: 4.001, 4.01, 4.1, and 5.

First, let’s calculate f(x)f(x) at the points x1=4x_1 = 4 and x2x_2 values.

  1. Calculate f(4)f(4):

f(4)=2(4)212(4)+10=2(16)48+10=3248+10=6f(4) = 2(4)^2 - 12(4) + 10 = 2(16) - 48 + 10 = 32 - 48 + 10 = -6

Now, we will calculate f(x2)f(x_2) for each x2x_2 value and then use the secant slope formula:

1. For x2=4.001x_2 = 4.001:

f(4.001)=2(4.001)212(4.001)+10=2(16.008001)48.012+10=32.01600248.012+10=5.995998f(4.001) = 2(4.001)^2 - 12(4.001) + 10 = 2(16.008001) - 48.012 + 10 = 32.016002 - 48.012 + 10 = -5.995998

Secant slope: f(4.001)f(4)4.0014=5.995998(6)0.001=0.0040020.001=4.002\frac{f(4.001) - f(4)}{4.001 - 4} = \frac{-5.995998 - (-6)}{0.001} = \frac{0.004002}{0.001} = 4.002

2. For x2=4.01x_2 = 4.01:

f(4.01)=2(4.01)212(4.01)+10=2(16.0801)48.12+10=32.160248.12+10=5.9598f(4.01) = 2(4.01)^2 - 12(4.01) + 10 = 2(16.0801) - 48.12 + 10 = 32.1602 - 48.12 + 10 = -5.9598

Secant slope: f(4.01)f(4)4.014=5.9598(6)0.01=0.04020.01=4.02\frac{f(4.01) - f(4)}{4.01 - 4} = \frac{-5.9598 - (-6)}{0.01} = \frac{0.0402}{0.01} = 4.02

3. For x2=4.1x_2 = 4.1:

f(4.1)=2(4.1)212(4.1)+10=2(16.81)49.2+10=33.6249.2+10=5.58f(4.1) = 2(4.1)^2 - 12(4.1) + 10 = 2(16.81) - 49.2 + 10 = 33.62 - 49.2 + 10 = -5.58

Secant slope: f(4.1)f(4)4.14=5.58(6)0.1=0.420.1=4.2\frac{f(4.1) - f(4)}{4.1 - 4} = \frac{-5.58 - (-6)}{0.1} = \frac{0.42}{0.1} = 4.2

4. For x2=5x_2 = 5:

f(5)=2(5)212(5)+10=2(25)60+10=5060+10=0f(5) = 2(5)^2 - 12(5) + 10 = 2(25) - 60 + 10 = 50 - 60 + 10 = 0

Secant slope: f(5)f(4)54=0(6)1=61=6\frac{f(5) - f(4)}{5 - 4} = \frac{0 - (-6)}{1} = \frac{6}{1} = 6

Table of Secant Slopes:

x2x_2Secant Slope
4.0014.002
4.014.02
4.14.2
56

Do you have any questions or need more details?

Here are some relative questions for practice:

  1. How would you compute the secant slope if the function was f(x)=3x2+5x7f(x) = 3x^2 + 5x - 7?
  2. What happens to the secant slope as x2x_2 approaches x1x_1?
  3. Can you calculate the secant slope if x1=3x_1 = 3 and x2=6x_2 = 6 for the function f(x)=x2xf(x) = x^2 - x?
  4. What is the relationship between secant slope and tangent slope?
  5. How does the secant line change as x2x_2 becomes further from x1x_1?

Tip: The secant line slope approaches the tangent slope as the interval between the two points gets smaller.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Secant Slope
Difference Quotient

Formulas

f(x) = 2x^2 - 12x + 10
Secant Slope = (f(x_2) - f(x_1)) / (x_2 - x_1)

Theorems

Secant Line Slope Theorem

Suitable Grade Level

Grades 9-12