Problem 7 - Algebra 2

Question

Write an equivalent exponential or logarithmic equation. 7\. \(e^{x}=4\)

Step-by-Step Solution

Answer

\(x = \ln{4}\).

Step 1: Identify the Base of the Exponential Equation

The given exponential equation is \(e^{x} = 4\). Here, the base is \(e\), which is the natural exponential base, approximately equal to 2.718.

Step 2: Convert Exponential Equation to Logarithmic Form

To convert the exponential equation \(e^{x} = 4\) to logarithmic form, we need to use the property that when \(a^b = c\), then \(b = \log_a{c}\). Thus, our equation becomes \(x = \ln{4}\), where \(\ln\) denotes the natural logarithm with base \(e\).

Key Concepts

Natural Logarithm

A natural logarithm is a logarithm with a special base, specifically the number \(e\), which is approximately 2.718. The natural logarithm of a number \(x\) is usually written as \(\ln{x}\). Rather than working with large numbers through multiplication, logarithms help us simplify calculations by transforming multiplication into addition. This is especially handy with the constant \(e\), which often appears in growth and decay problems.

Logarithms can be visualized as the flip side of exponentials. For example, while \(e^{x}\) represents exponents `using` a base \(e\) to grow a number through repeated multiplication by \(e\), \(\ln{x}\) figures out the power to which you need to raise \(e\) to obtain \(x\).
This conversion finds numerous applications in science and mathematics, as it simplifies complex power relationships into more manageable linear relationships.

Exponential Functions

Exponential functions are mathematical functions of the form \(a^{f(x)}\), where the base \(a\) is a constant and \(f(x)\) is an exponent that specifies how many times \(a\) is multiplied by itself. Exponential functions grow much faster than linear or polynomial functions. A common exponential function is \(e^{x}\), where \(e\) is Euler's number (approximately 2.718).

These functions are crucial in real-world situations. They describe growth processes such as population growth, radioactive decay, and even compound interest. The key property of exponential functions is their constant percentage growth rate. For example, in the equation \(e^{x} = 4\), you see how the function \(e^{x}\) represents a transformation that has real and significant implications, such as calculating continuous growth rates in finance or biology.

Conversion Between Forms

Converting between exponential and logarithmic forms is a crucial skill in mathematics. It allows you to view and solve equations from different perspectives. The fundamental idea is: if you have an equation \(a^b = c\), you can convert it to a logarithmic form as \(b = \log_a{c}\) and vice versa.

Take the example \(e^{x} = 4\). The exponential form states that raising \(e\) to the power \(x\) results in 4. Turning this to its logarithmic counterpart, we find \(x = \ln{4}\). This transformation is powerful because it simplifies solving for unknowns, like when checking if a problem involves exponential growth or decay.

• Exponential form: Useful to model scenarios where there is repeated multiplication or growing processes.
• Logarithmic form: Essential for analyzing growth boundaries or change ratios.

Understanding these conversions opens a trove of new techniques for solving mathematical problems, bridging the gap between different mathematical areas.