Skip to main content
Ch. 4 - Exponential and Logarithmic Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 5, Problem 65

The figure shows the graph of f(x) = ln x. In Exercises 65–74, use transformations of this graph to graph each function. Graph and give equations of the asymptotes. Use the graphs to determine each function's domain and range. g(x) = ln (x+2)
Graph of the natural logarithm function f(x) = ln x with points, vertical asymptote at x=0, and labeled axes.

Verified step by step guidance
1
Identify the base function: The given function is \( f(x) = \ln x \), which is the natural logarithm function with domain \( (0, \infty) \) and range \( (-\infty, \infty) \). Its vertical asymptote is the line \( x = 0 \).
Analyze the transformation: The function \( g(x) = \ln (x + 2) \) represents a horizontal shift of the base function \( f(x) = \ln x \) to the left by 2 units because the input \( x \) is replaced by \( x + 2 \).
Determine the new domain: Since the argument of the logarithm must be positive, set \( x + 2 > 0 \). Solve this inequality to find the domain of \( g(x) \).
Find the new vertical asymptote: The vertical asymptote occurs where the argument of the logarithm is zero, so set \( x + 2 = 0 \) and solve for \( x \) to find the equation of the asymptote.
Describe the range: The range of \( g(x) = \ln (x + 2) \) remains the same as the base function \( f(x) = \ln x \), which is \( (-\infty, \infty) \), because vertical shifts or horizontal shifts do not affect the range of the logarithmic function.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
5m
Was this helpful?

Key Concepts

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

Natural Logarithm Function

The natural logarithm function, denoted as ln(x), is the inverse of the exponential function e^x. It is defined only for positive x-values and has a vertical asymptote at x = 0. Understanding its basic shape and properties is essential for graph transformations.
Recommended video:
2:51
The Natural Log

Graph Transformations

Graph transformations involve shifting, stretching, or reflecting the graph of a function. For g(x) = ln(x + 2), the graph of ln(x) shifts horizontally left by 2 units. Recognizing how changes inside the function's argument affect the graph helps in sketching and analyzing new functions.
Recommended video:
5:25
Intro to Transformations

Domain, Range, and Asymptotes

The domain of ln(x) is (0, ∞), and its range is (-∞, ∞). Horizontal or vertical shifts affect the domain and location of asymptotes. For g(x) = ln(x + 2), the vertical asymptote moves to x = -2, and the domain becomes (-2, ∞), while the range remains all real numbers.
Recommended video:
4:48
Determining Horizontal Asymptotes
Related Practice
Textbook Question

In Exercises 64–73, solve each exponential equation. Where necessary, express the solution set in terms of natural or common logarithms and use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. 2^(4x-2) = 64

Textbook Question

Use properties of logarithms to condense each logarithmic expression. Write the expression as a single logarithm whose coefficient is 1. Where possible, evaluate logarithmic expressions without using a calculator. 12(log5x+log5y)2log5(x+1)\(\frac{1}{2}\) \(\left\)( \(\log\)_5 x + \(\log\)_5 y \(\right\)) - 2 \(\log\)_5 (x + 1)

Textbook Question

The figure shows the graph of f(x) = log x. In Exercises 59–64, use transformations of this graph to graph each function. Graph and give equations of the asymptotes. Use the graphs to determine each function's domain and range.

g(x) = 1-log x

6
views
Textbook Question

Solve each logarithmic equation in Exercises 49–92. Be sure to reject any value of xx that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. lnx+3=1\(\ln\]\sqrt{x+3}\)=1

1
views
Textbook Question

Use properties of logarithms to condense each logarithmic expression. Write the expression as a single logarithm whose coefficient is 1. Where possible, evaluate logarithmic expressions without using a calculator. 13[2ln(x+5)lnxln(x24)]\(\frac{1}{3}\) \(\left\)[ 2 \(\ln\)(x + 5) - \(\ln\) x - \(\ln\) (x^2 - 4) \(\right\)]

7
views
Textbook Question

In Exercises 64–73, solve each exponential equation. Where necessary, express the solution set in terms of natural or common logarithms and use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. 10^x = 7000

1
views