Ch. 2 - Functions and Graphs

Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook

Blitzer 8th Edition

Ch. 2 - Functions and Graphs

Problem 33

Chapter 3, Problem 33

Find f−g and determine the domain for each function. f(x) = x -5, g(x) = 3x²

Verified step by step guidance

Identify the given functions: $f(x) = x - 5$ and $g(x) = 3x^{2}$.

Find the difference of the functions, which is $f - g$. This means subtract $g(x)$ from $f(x)$: write the expression as $f(x) - g(x)$.

Substitute the given functions into the expression: $f(x) - g(x) = (x - 5) - (3x^{2})$.

Simplify the expression by removing parentheses and combining like terms: $x - 5 - 3x^{2}$.

Determine the domain of the new function $f - g$. Since both $f(x)$ and $g(x)$ are polynomials, their domain is all real numbers, so the domain of $f - g$ is also all real numbers.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Function Operations (Subtraction)

Function subtraction involves creating a new function by subtracting the output of one function from another for the same input value. For functions f and g, (f - g)(x) = f(x) - g(x). This operation combines the two functions algebraically and is essential for manipulating and analyzing function behavior.

Domain of a Function

The domain of a function is the set of all input values (x-values) for which the function is defined. When performing operations like subtraction on functions, the domain of the resulting function is the intersection of the domains of the original functions, ensuring all expressions are valid.

Polynomial Functions and Their Domains

Polynomial functions, such as f(x) = x - 5 and g(x) = 3x², are defined for all real numbers because they involve only powers of x with real coefficients. Understanding that polynomials have domains of all real numbers simplifies determining the domain of combined functions like f - g.

Recommended video:

06:04

Introduction to Polynomial Functions

Related Practice

Textbook Question

Which graphs in Exercises 29–34 represent functions that have inverse functions?

Textbook Question

Use the graph of y = f(x) to graph each function g. g(x) = f(x)+2

Textbook Question

Evaluate each function at the given values of the independent variable and simplify. h(x) = x³ − x + 1 d. h (3a)

Textbook Question

Evaluate each function at the given values of the independent variable and simplify. $f (r) = \sqrt{r + 6} + 3$

$a period f of negative 6$

Textbook Question

Evaluate each function at the given values of the independent variable and simplify. h(x) = x³ − x + 1 c. h (-x)

Textbook Question

Write the standard form of the equation of the circle with the given center and radius. Center (3, 2), r = 5

views