Problem 26 - Applied Mathematics: For the Managerial, Life, and Social Sciences

Question

Use the laws of logarithms to expand and simplify the expression. $$\ln x(x+1)(x+2)$$

Step-by-Step Solution

Answer

Using the product rule of logarithms, the given expression can be expanded and simplified as: \(\boxed{\ln x(x+1)(x+2) = \ln x + \ln(x+1) + \ln(x+2)}\)

Step 1: Identify the Expression

We need to evaluate or simplify: \(\ln x(x+1)(x+2)\).

Step 2: Apply Order of Operations

Following the order of operations (PEMDAS/BODMAS), we simplify the expression step by step, handling parentheses, exponents, multiplication/division, then addition/subtraction.

Step 3: Compute the Result

Carrying out the operations systematically, we arrive at the result.

Step 4: State the Result

Using the product rule of logarithms, the given expression can be expanded and simplified as: \(\boxed{\ln x(x+1)(x+2) = \ln x + \ln(x+1) + \ln(x+2)}\)

Key Concepts

Product Rule in Logarithms

When dealing with logarithms, one of the key properties we often use is the Product Rule. Logarithms allow us to break down multiplication into simpler pieces using this rule. Think of it like converting a big multiplication problem into smaller addition tasks. The Product Rule states that for any positive numbers \(a\), \(b\), and base \(c\):\[\log_c(ab) = \log_c a + \log_c b\]In this equation, multiplying two numbers \(a\) and \(b\) and taking the logarithm of the product is the same as adding their individual logarithms. This is very useful for simplifying complex expressions. For example, if you have \(\ln(abc)\), by using the product rule, this simplifies to \(\ln a + \ln b + \ln c\). Each term becomes much easier to handle separately. This principle of breaking down products is foundational in working with logarithmic expressions.

Expanding Logarithms

Expanding logarithms involves taking a more complicated logarithmic expression and breaking it apart into simpler pieces. It's like taking a cluttered room and organizing everything into boxes. This approach helps make intricate equations more manageable by using the properties of logarithms. For the expression \(\ln(x(x+1)(x+2))\), the goal is to expand it using the product rule. The expression encompasses the multiplication of \(x\), \(x+1\), and \(x+2\). Using our rules, it expands to:- \(\ln x\) for the first term,- \(\ln(x+1)\) for the second,- and \(\ln(x+2)\) for the third.This method results in the sum: \(\ln x + \ln(x+1) + \ln(x+2)\). Each component is isolated and simplified, making it easier to work with or further analyze. Understanding how to expand logarithms is crucial for solving higher-level algebra problems, as it transforms a potentially daunting equation into something more straightforward.

Simplifying Logarithmic Expressions

Simplifying logarithmic expressions is all about making equations easier to understand and solve. It's like untangling a knot into a smooth strand. After using the product rule and expansion, the next step is simplification, if needed.Simplifying involves checking if any portions of the expression can be combined or further reduced. While the example expression \(\ln x + \ln(x+1) + \ln(x+2)\) is fully expanded, simplification may sometimes involve:- Combining like terms- Using additional logarithmic laws like the Quotient Rule or Power RuleFor the given expression, each term is already in its simplest form as separate logarithmic components. The simplification process in this context has reached its limit, as no further reduction or manipulation can simplify \(\ln x\), \(\ln(x+1)\), or \(\ln(x+2)\) within the provided expression. Mastery of simplifying expressions lies in recognizing when and where expressions can be adjusted without changing their meanings.