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 68

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. 8x=121438^x = 12143

Verified step by step guidance
1
Start with the given exponential equation: \$8^x = 12143$.
To solve for \(x\), take the natural logarithm (or common logarithm) of both sides to utilize the logarithm property that allows exponents to be brought down: \(\ln(8^x) = \ln(12143)\).
Apply the logarithm power rule: \(x \cdot \ln(8) = \ln(12143)\).
Isolate \(x\) by dividing both sides of the equation by \(\ln(8)\): \(x = \frac{\ln(12143)}{\ln(8)}\).
Use a calculator to evaluate the logarithms and compute the decimal approximation of \(x\), rounding your answer to two decimal places.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

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

Exponential Equations

An exponential equation is one in which the variable appears in the exponent. Solving such equations often involves rewriting the equation to isolate the exponential expression and then applying logarithms to solve for the variable.
Recommended video:
5:47
Solving Exponential Equations Using Logs

Logarithms and Their Properties

Logarithms are the inverse operations of exponentiation. They allow us to solve equations where the variable is an exponent by converting the exponential form into a logarithmic form, making it easier to isolate and solve for the variable.
Recommended video:
5:36
Change of Base Property

Using Calculators for Approximations

Calculators can evaluate logarithms and provide decimal approximations of solutions. After expressing the solution in logarithmic form, a calculator helps find a numerical value, often rounded to a specified number of decimal places for practical use.
Recommended video:
5:47
Solving Exponential Equations Using Logs
Related Practice
Textbook Question

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.

h(x) = ln (2x)

1360
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) \(\right\)]

1002
views
Textbook Question

Solve each logarithmic equation in Exercises 49–92. Be sure to reject any value of x 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. log5 x+log5(4x−1)=1

861
views
Textbook Question

Solve each logarithmic equation in Exercises 49–92. Be sure to reject any value of x 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. log3(x+6)+log3(x+4)=1

1102
views
Textbook Question

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. h(x) = ln(x/2)

735
views
Textbook Question

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) = 2 ln x

554
views