Problem 37

Question

Use the properties of logarithms to simplify the expression. $$\log _{4} 4^{3 x}$$

Step-by-Step Solution

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Answer
The simplified form of the given logarithmic expression is \(3x\).
1Step 1: Identify the property to use
Since the expression involves a logarithm and an exponent with the same base, this is a clear indication that we can use the property of logarithms that says \(log_{b} b^x = x\)
2Step 2: Apply the property of logarithms
Substitute the values into the logarithmic property. We have \(log_{4} 4^{3x}\) equals to the exponent of the \(4\), which is \(3x\).

Key Concepts

ExponentSimplificationMathematics Problem Solving
Exponent
An exponent refers to the number used to indicate how many times a base is multiplied by itself. For instance, in the expression \(4^{3x}\), the number 4 is the base, and \(3x\) is the exponent. This means that 4 is multiplied by itself '3x' times. Exponents provide a concise way to express repeated multiplication and is an essential concept in mathematics, especially when working with logarithms.

Exponents follow certain rules which aid in simplifying expressions. Some of these rules include the power rule, which states \((a^m)^n = a^{mn}\), and the product rule, which states \(a^m \times a^n = a^{m+n}\). Understanding how exponents work is crucial when applying logarithmic properties, as seen in the exercise.

The logarithm rule that is useful here turns the exponent into a simple coefficient. When we take the logarithm of a number that is an exponent of the base, the exponent can be brought down as a multiplier. This is one reason why logs are so handy when dealing with exponential functions, they can simplify complex operations.
Simplification
Simplification in mathematics involves reducing expressions to their most basic form. The primary aim is to make expressions easier to handle or solve. Here, simplifying \(\log _{4} 4^{3x}\) involves recognizing patterns and applying known rules, particularly the properties of logarithms.

The property used in this exercise, \( \log_{b} b^x = x \), is a specific logarithm rule that significantly simplifies expressions where the base of the logarithm and the base of the exponent are the same. This property tells us that the logarithm of a number where the number itself is the base raised to some power, simplifies directly to that power (or exponent).

By applying this property, what might initially look like a complex logarithmic expression is reduced to \(3x\). Simplification reduces the cognitive load required, making subsequent calculations straightforward. This is why recognizing simplification opportunities is key in effectively solving mathematical problems.
Mathematics Problem Solving
Mathematics problem solving is about applying the right strategies and understanding the concepts to arrive at a solution efficiently. With logarithmic expressions, recognizing the properties that apply can drastically simplify the process.

In the given exercise, if we correctly identify that the logarithmic property \( \log_{b} b^x = x \) applies, we immediately jump to the solution without much arithmetic. This skill comes from being familiar with various logarithmic and algebraic properties, and knowing which one to apply at the right moment.

Effective problem solving involves:
  • Identifying patterns or properties that can simplify components of the problem.
  • Breaking the problem into manageable parts.
  • Using logical reasoning to move towards a solution.
Familiarity with mathematical concepts like logarithms and exponents, therefore, becomes a vital tool in any problem solver's toolset. The ultimate goal is not only to find the solution but to find it in the most efficient manner possible.