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Ch. 4 - Exponential and Logarithmic Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 5, Problem 103

In Exercises 101–104, write each equation in its equivalent exponential form. Then solve for x. log4x=-3

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Recall the definition of logarithm: if \( \log_b a = c \), then the equivalent exponential form is \( b^c = a \).
Apply this definition to the given equation \( \log_4 x = -3 \). Rewrite it as \( 4^{-3} = x \).
Express \( 4^{-3} \) as a fraction with a positive exponent: \( 4^{-3} = \frac{1}{4^3} \).
Calculate \( 4^3 \) by multiplying 4 by itself three times: \( 4 \times 4 \times 4 \).
Write the final expression for \( x \) as \( x = \frac{1}{4^3} \), which is the solution in exponential form.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Definition of Logarithms

A logarithm answers the question: to what exponent must the base be raised to produce a given number? For example, log_b(a) = c means b^c = a. Understanding this definition is essential to convert between logarithmic and exponential forms.
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Converting Logarithmic Equations to Exponential Form

To rewrite a logarithmic equation like log_b(x) = y in exponential form, express it as b^y = x. This conversion simplifies solving for the variable by changing the equation into a more straightforward exponential expression.
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Solving Logarithmic Equations

Solving Exponential Equations

Once the equation is in exponential form, solving for the variable involves evaluating powers or roots. For example, if 4^{-3} = x, calculate 4^{-3} by using the negative exponent rule, which means 1 divided by 4^3.
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