/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 43 Let \(f(x)=2 x-3, g(x)=x^{2}+3 x... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Let \(f(x)=2 x-3, g(x)=x^{2}+3 x,\) and \(h(x)=\frac{x+3}{2} .\) Find the following. See Examples 4 and \(5 .\) $$(f \circ g)(x)$$

Short Answer

Expert verified
\(f(g(x)) = 2x^2 + 6x - 3\)

Step by step solution

01

Understand Function Composition

Function composition involves applying one function to the results of another. Symbolically, \(f \circ g\)(x) means \(f(g(x))\). We first need to find an expression for g(x) and then substitute this into the function f(x).
02

Write Down each Function

Write down the given functions: \(f(x) = 2x - 3 \, g(x) = x^2 + 3x\).
03

Substitute g(x) into f(x)

Replace x in \(f(x)\) with \(g(x)\). Thus, \(f(g(x))\) becomes \(f(x^2 + 3x)\).
04

Compute f(g(x))

Substitute \(x^2 + 3x\) into \(f(x) = 2x - 3\). You get \(f(x^2 + 3x) = 2(x^2 + 3x) - 3\), simplifying this gives \[f(g(x)) = 2x^2 + 6x - 3.\]

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Composite Functions
Composite functions are a way to combine two functions in a specific order. The notation \(f \circ g\)(x) means that you first apply the function g to x, and then apply the function f to the result of g(x). This is written as f(g(x)).

Let's break it down with an example from the exercise. Here, we have f(x) = 2x - 3 and g(x) = x^2 + 3x. To find \(f \circ g\)(x),\ you substitute g(x) into f(x). So, first find g(x), and then plug this result into f(x).

This concept is powerful in various fields like physics and economics, where multiple processes are combined. To get the final result, always remember to follow the order of operations: apply g and then f.
Algebraic Functions
Algebraic functions involve basic operations like addition, subtraction, multiplication, and division applied to variables or constants. They can include polynomials, rational expressions, and radicals.

In our original exercise, the given functions f(x) = 2x - 3 and g(x) = x^2 + 3x are algebraic functions. Each function involves basic algebraic operations.

To solve for \(f \circ g\)(x),\ we replace x in f(x) with the function g(x). The algebraic manipulation to simplify f(g(x)) involves distributing the multiplication through the terms and combining like terms.

Algebraic functions are everywhere. Understanding how to manipulate them is crucial for solving more complex problems in calculus and other areas of mathematics.
Substitution Method
The substitution method is a powerful technique used to evaluate composite functions. This involves replacing a variable in one function with another function.

In the exercise, we need to evaluate f(g(x)). Here's how: write down f(x) and g(x). Substitute g(x) = x^2 + 3x into f(x). Your equation becomes f(x^2 + 3x). Next, replace the x in f(x) with x^2 + 3x. This gives f(g(x)) = 2(x^2 + 3x) - 3.

Simplify by distributing 2 through x^2 + 3x and combining like terms: 2x^2 + 6x - 3.

This substitution method helps you easily evaluate complex expressions and is used in many areas such as solving differential equations and integrating functions.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Let \(f(x)=x^{2}\) and \(g(x)=x+5 .\) Determine whether each of these statements is true or false. $$\text { If } p(x)=x^{2}+5, \text { then } p=g \circ f$$

Let \(f(x)=x^{2}\) and \(g(x)=x+5 .\) Determine whether each of these statements is true or false. $$g(3)=8$$

Solve each problem. At the Windrush Trace apartment complex all living rooms are square, but the length of \(x\) feet may vary. The cost of carpeting a living room is S18 per square yard plus a \(\$ 50\) installation fee. Find the function \(C(x)\) that gives the total cost of carpeting a living room of length \(x .\) The manager has an invoice for the total cost of a living room carpeting job but does not know in which apartment it was done. Find the function \(C^{-1}(x)\) that gives the length of a living room as a function of the total cost of the carpeting job \(x .\)

Find the inverse of each function. $$g(x)=(x+5)^{2} \text { for } x \geq-5$$

Solve each problem. The distance that it takes a car to stop is a function of the speed and the drag factor. The drag factor is a measure of the resistance between the tire and the road surface. The formula \(S=\sqrt{30 L D}\) is used to determine the minimum speed \(S\) [ in miles per hour (mph)] for a car that has left skid marks of length \(L\) feet ( \(\mathrm{ft}\) ) on a surface with drag factor \(D\). a) Find the minimum speed for a car that has left skid marks of length 50 ft where the drag factor is 0.75 b) Does the drag factor increase or decrease for a road surface when it gets wet? c) Write \(L\) as a function of \(S\) for a road surface with drag factor 1 and graph the function. (GRAPH AND IMAGE CAN'T COPY)

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.