Problem 62 - Algebra and Trigonometry Real Mathematics, Real People

Question

Write the logarithmic equation in exponential form. For example, the exponential form of \(\ln 5=1.6094\). . . is \(e^{1.6094 \cdots}=5.\) $$\ln 4=1.3862 . . .$$

Step-by-Step Solution

Answer

The exponential form of \(\ln 4 = 1.3862... \) is \(e^{1.3862...} = 4\).

Step 1: Identify the given values

In the equation \(\ln 4 = 1.3862... \), we can see that \('a'\) is 4 and \('b'\) is approximately 1.3862.

Step 2: Convert to exponential form

Using the given information, our task is to rewrite \(\ln 4 = 1.3862... \) into the form \(e^{b} = a\). Substituting \('b'\) as 1.3862 and \('a'\) as 4, we get \(e^{1.3862...} = 4\).

Key Concepts

Natural Logarithm

The natural logarithm, represented by the symbol \(\ln\), is a mathematical function that is the inverse of the function of exponential growth. Specifically, if \(e^x = y\), then \(\ln y = x\). The base of the natural logarithm is Euler's number \(e\), which is approximately 2.71828. Understanding natural logarithms is critical for solving exponential equations, as they allow us to reverse the process of exponentiation and find the original exponent given the result.

For example, in the given exercise, we see that \(\ln 4 = 1.3862...\). This equation is telling us that \(e\) raised to the power of approximately 1.3862 equals 4. When solving problems of this type, recognizing the relationship between the natural logarithm and exponentiation is key to converting from logarithmic to exponential form effectively.

Exponential Equations

Exponential equations feature an unknown variable in the exponent and are of the general form \(a^x = b\), where \(a\) is a positive real number not equal to 1, and \(x\) and \(b\) are also real numbers. To solve exponential equations, one often employs logarithms because they are the inverse functions to exponentiation. This property allows us to isolate the variable \(x\) and solve for it. In converting a logarithmic statement to its exponential form, recall the fundamental principle that if \(\log_a(b) = c\), then the equivalent exponential form is \(a^c = b\).

Taking the exercise as an example, by converting \(\ln 4 = 1.3862...\) into the form \({e^{1.3862...}} = 4\), we have effectively utilized the concept of exponential equations to find the base \(e\) exponent that results in 4.

Euler's Number e

Euler's number, denoted as \(e\), is a fundamental mathematical constant approximately equal to 2.71828. It is the base of the natural logarithm and has unique properties that make it extremely important in mathematics, particularly in calculus and complex analysis. Its unique rate of growth, such that the function \(e^x\) is equal to its derivative, makes \(e\) an ideal base for continuous growth processes.

In the context of the exercise, when we talk about converting \(\ln 4 = 1.3862...\) into exponential form, it is critical to recognize that \(e\) is implicitly the base of the natural logarithm. Thus, the equation is stating that when \(e\) is raised to the power of approximately 1.3862, it equals 4. It highlights \(e\)'s role in logarithmic and exponential expressions and underscores its significance in a wide range of mathematical and real-world applications, from compound interest to population models.