Problem 30 - Intermediate Algebra

Question

For Problems \(21-40\), evaluate each expression. $$ \log _{10} 10 $$

Step-by-Step Solution

Answer

The evaluation of \( \log _{10} 10 \) is 1.

Step 1: Understand the Logarithm

The expression given is \( \log_{10} 10 \). A logarithm is the inverse operation to exponentiation. Specifically, the logarithm \( \log_b a \) answers the question: 'To what exponent must we raise \( b \) to get \( a \)?' In this case, \( b = 10 \) and \( a = 10 \).

Step 2: Apply the Basic Logarithm Rule

For any positive number \( b \), the logarithm \( \log_b b \) is always \( 1 \). This is because raising \( b \) to the power of \( 1 \) results in \( b \). So, \( \log_{10} 10 = 1 \).

Step 3: Verify the Result

To confirm, consider the equivalent statement in exponential form: \( 10^x = 10 \). The value of \( x \) that satisfies this equation is \( 1 \), thus verifying \( \log_{10} 10 = 1 \).

Key Concepts

Exponential Function

An exponential function is a mathematical expression where a constant base is raised to a variable exponent. The general form is \( a^x \), where \( a \) is a constant and \( x \) is the variable. This type of function shows how quantities grow or decay rapidly over time. For example:

• Population growth, which can double every time period.
• Exponential decay, like radioactive decay where the material diminishes rapidly over time.

In the realm of logarithms, exponential functions play a crucial role. They are considered the building blocks of logarithms. The relationship between the two is that logarithms are the "undoing" of these exponential operations, which brings us to the concept of inverse operations.

Inverse Operation

In mathematics, an inverse operation reverses the effect of another operation. Addition and subtraction, or multiplication and division, are simple examples of inverse operations. When it comes to exponential functions and logarithms, these are each other's inverses.

Here's how it works:

• An exponential function such as \( 10^x \) can be inverted by \( \log_{10} \).
• When applying \( \log \) to an exponential equation, you retrieve the exponent, effectively undoing the exponentiation.

For instance, if you have \( 10^1 = 10 \), using the logarithmic rule \( \log_{10} 10 = 1 \) brings us back to the power of 1. This demonstrates the nature of inverse operations, where one operation cancels out the effect of the other, returning you to the original variable or value.

Logarithmic Rule

The logarithmic rule is a fundamental principle showing the inherent properties of logarithms. A key logarithmic rule used in the exercise is \( \log_b b = 1 \). This rule explains that the logarithm of a base raised to its own power will always be the exponent, which is 1. This happens because raising a number to the power of 1 yields the number itself.

In simple terms, if you see \( \log_{10} 10 \), you're being asked, "To what power do I raise 10 to get 10?" The answer is 1. The importance of this rule lies in its ability to simplify logarithmic expressions and equations by providing straightforward solutions, making it easier to solve or rearrange them.

Understanding and applying this rule allows for efficient handling of logarithmic expressions across different scenarios, from simple evaluations to complex logarithmic operations.