Math Problem Statement

Graph the composite function g(f(x)) where f(x) = -2x - 5 and g(x) = x - 1.

Solution

We are asked to graph the composite function g(f(x))g(f(x)), where:

f(x)=2x5andg(x)=x1f(x) = -2x - 5 \quad \text{and} \quad g(x) = x - 1

Step 1: Find the composite function g(f(x))g(f(x))

To compute g(f(x))g(f(x)), we substitute f(x)f(x) into g(x)g(x). Specifically, since g(x)=x1g(x) = x - 1, we replace xx in g(x)g(x) with f(x)f(x):

g(f(x))=g(2x5)=(2x5)1g(f(x)) = g(-2x - 5) = (-2x - 5) - 1

Simplifying this:

g(f(x))=2x51=2x6g(f(x)) = -2x - 5 - 1 = -2x - 6

Step 2: Graphing the function

The composite function g(f(x))=2x6g(f(x)) = -2x - 6 is a linear function. Its slope is 2-2, and its y-intercept is 6-6.

To graph this, we follow these steps:

  1. Plot the y-intercept at (0,6)(0, -6).
  2. Use the slope 2-2, which indicates that for every 1 unit increase in xx, yy decreases by 2 units. From the y-intercept, move 1 unit to the right and 2 units down to find another point on the line.
  3. Connect these points to form a straight line.

Would you like me to generate a graph for this function?

Follow-up questions:

  1. How do you compute the composite of two functions in general?
  2. What is the significance of the slope in a linear function?
  3. How does the y-intercept influence the graph of a linear equation?
  4. What is the difference between f(g(x))f(g(x)) and g(f(x))g(f(x))?
  5. Can composite functions always be simplified into basic forms like linear functions?

Tip: Always substitute carefully when computing composite functions to avoid errors in simplification!

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions
Composite Functions
Linear Equations

Formulas

g(f(x)) = g(-2x - 5) = (-2x - 5) - 1
g(f(x)) = -2x - 6

Theorems

Composition of Functions

Suitable Grade Level

Grades 9-12