/*! 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 40 Solve the logarithmic equation. ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Solve the logarithmic equation. $$\ln x=-14$$

Short Answer

Expert verified
The solution to the given equation \(x = e^{-14}\), or approximately \(x = 7.667647e^{-7}\).

Step by step solution

01

Convert the logarithm equation to Exponential form

Here, given that \(ln x = -14\) and recalling that \(ln\) is a logarithm in base \(e\), this equation can be written in exponential form as: \(e^{-14} = x\). This comes from the property that if \(ln x = a\), then \(x = e^a\).
02

Compute the exponential

Now, calculate the value of \(e^{-14}\) to obtain the value of \(x\). \(x = e^{-14}\) is approximately \(7.667647e^{-7}\), yet it is generally acceptable to leave the answer in exact form, \(x = e^{-14}\), unless instructed to give an approximation.

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.

Understanding the Natural Logarithm
The natural logarithm, denoted as \( \ln \), plays a pivotal role when solving logarithmic equations. It refers specifically to a logarithm with the base \( e \), where \( e \approx 2.71828\) and is a mathematical constant known as Euler's number. The natural logarithm of a number \(x\) essentially answers the question: 'To what power must we raise \(e\) to obtain \(x\)?' Hence, the equation \( \ln x = -14 \) suggests we are looking for a number that, when \(e\) is raised to its power, gives a result of \(x\).

In practical situations, natural logarithms are particularly useful in fields dealing with growth and decay processes, like biology and finance, because they naturally describe rates of change. Knowing the properties of the natural logarithm can also assist in understanding compound interest, population growth models, and half-life calculations in radioactive decay.
Exponential Form Conversion
When dealing with logarithms, it's often necessary to convert between logarithmic and exponential forms to simplify calculations and derive solutions. This conversion utilizes the foundational relationship between logarithms and exponents. To convert a logarithmic equation like \( \ln x = -14 \) into exponential form, recall the intrinsic rule: if \( \ln a = b \), then the equivalent expression is \( e^b = a \).

So, for the given problem, we restate \( \ln x = -14 \) as \( x = e^{-14} \). This takes advantage of the logarithm's role as an exponent to find the original quantity. This exponential form conversion lays the groundwork for finding precise solutions or making approximations. Such transformations are not limited to natural logarithms and apply to any logarithmic base, greatly enhancing the versatility of solving logarithmic equations.
Properties of Logarithms
To master solving logarithmic equations, a firm grasp of the properties of logarithms is invaluable. These properties include the product, quotient, and power rules which make manipulating and simplifying logarithms easier. For instance, the product rule states that \( \ln(ab) = \ln a + \ln b \), while the quotient rule marks that \( \ln(\frac{a}{b}) = \ln a - \ln b \). The power rule is especially relevant in the context of the equation \( \ln x = -14 \) since it dictates that \( \ln(a^b) = b\cdot\ln a \), allowing us to move back and forth between the logarithm of an exponentiated value and the multiplication of the exponent with a logarithm.

Employing these properties in combination with the conversion between logarithmic and exponential forms can significantly simplify the process of finding unknown variables within logarithmic equations. They are integral tools in a mathematician’s toolkit and can be useful in a wide variety of mathematical disciplines, from algebra to advanced calculus.

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

Use the regression feature of a graphing utility to find an exponential model \(y=a b^{x}\) for the data and identify the coefficient of determination. Use the graphing utility to plot the data and graph the model in the same viewing window. $$(-3,102.2),(0,80.5),(3,67.8),(6,58.2),(10,55.0)$$

An exponential model of the form \(y=a b^{x}\) can be rewritten as a natural exponential model of the form _________.

A beaker of liquid at an initial temperature of \(78^{\circ} \mathrm{C}\) is placed in a room at a constant temperature of \(21^{\circ} \mathrm{C}\) The temperature of the liquid is measured every 5 minutes for a period of \(\frac{1}{2}\) hour. The results are recorded in the table, where \(t\) is the time (in minutes) and \(T\) is the temperature (in degrees Celsius). $$\begin{array}{|c|c|}\hline \text { Time, } t 0 & \text { Temperature, } T\\\\\hline 0 & 78.0^{\circ} \\\5 & 66.0^{\circ} \\\10 & 57.5^{\circ} \\\15 & 51.2^{\circ} \\\20 & 46.3^{\circ} \\\25 & 42.5^{\circ} \\\30 & 39.6^{\circ} \\\\\hline\end{array}$$ (a) Use the regression feature of a graphing utility to find a linear model for the data. Use the graphing utility to plot the data and graph the model in the same viewing window. Do the data appear linear? Explain. (b) Use the regression feature of the graphing utility to find a quadratic model for the data. Use the graphing utility to plot the data and graph the model in the same viewing window. Do the data appear quadratic? Even though the quadratic model appears to be a good fit, explain why it might not be a good model for predicting the temperature of the liquid when \(t=60.\) (c) The graph of the temperature of the room should be an asymptote of the graph of the model. Subtract the room temperature from each of the temperatures in the table. Use the regression feature of the graphing utility to find an exponential model for the revised data. Add the room temperature to this model. Use the graphing utility to plot the original data and graph the model in the same viewing window. (d) Explain why the procedure in part (c) was necessary for finding the exponential model.

The percent \(p\) (in decimal form) of the United States population who own a smartphone is given by $$p=\frac{1}{1+e^{-(t-93) / 22.5}}$$ where \(t\) is the number of months after smartphones were available on the market. Find the number of months \(t\) when the percent of the population owning smartphones is (a) \(50 \%\) and (b) \(80 \%\).

Solve the logarithmic equation algebraically. Round the result to three decimal places. Verify your answer(s) using a graphing utility. $$\ln 2 x=1.5$$

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.