Chapter 13: Problem 38
Determine the value of the unknown. $$\log _{b} 625=4$$
Short Answer
Expert verified
The base \( b \) is 5.
Step by step solution
01
Understand the Exponential Form from Logarithmic Form
The logarithmic equation \( \log_b 625 = 4 \) can be rewritten in its exponential form. The definition of a logarithm states that \( \log_b a = c \) is equivalent to \( b^c = a \). Thus, we interpret \( \log_b 625 = 4 \) as \( b^4 = 625 \).
02
Rewrite the Exponential Equation
Now rewrite the exponential equation \( b^4 = 625 \). Our task is to find the value of \( b \), meaning we need to determine what number raised to the fourth power gives 625.
03
Evaluate the Fourth Root
To solve for \( b \), we take the fourth root of both sides of the equation: \( b = \sqrt[4]{625} \). The fourth root of 625 is found by identifying the number that when multiplied by itself four times equals 625.
04
Calculate Fourth Root of 625
Recognize that \( 625 = 5 \times 5 \times 5 \times 5 = 5^4 \). This indicates that \( b = 5 \) is the correct value since \( 5^4 = 625 \).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Exponential Form
Logarithmic equations are a vital part of mathematics, helping us make sense of exponential relationships. A logarithmic equation like \( \log_b 625 = 4 \) can be transposed into an exponential form, which is more intuitive for solving problems. This transformation acts as a translation tool between two mathematical worlds: logarithms and exponents. Here's how it works in our context:
Consider transforming equations back and forth as a way to strengthen your mathematical fluency and problem-solving skills.
- The equation \( \log_b 625 = 4 \) tells us that the base \( b \) raised to the power of 4 equals 625.
- Using the exponential form, this translates to \( b^4 = 625 \).
Consider transforming equations back and forth as a way to strengthen your mathematical fluency and problem-solving skills.
Fourth Root
Calculating roots is an essential math skill, and finding a fourth root helps solve equations like \( b^4 = 625 \). When we look for a fourth root, we search for a number which, when raised to the power of 4, results in our given number. Here, you want to find the value of \( b \) so that \( b^4 = 625 \).
Taking the fourth root of both sides gives us \( b = \sqrt[4]{625} \).
Taking the fourth root of both sides gives us \( b = \sqrt[4]{625} \).
- To determine this, consider what number multiplied by itself four times will yield 625.
- For instance, 625 can be rewritten as \( 5 \times 5 \times 5 \times 5 = 5^4 \).
Evaluating Exponents
Understanding and evaluating exponents is fundamental in mathematics, helping to decode expressions and solve equations. Exponents represent repeated multiplication of a number by itself. For example, the expression \( 5^4 \) means multiplying 5 by itself four times:
Practice regularly with different numbers to strengthen your skill in evaluating exponents, and you'll find it becomes second nature over time.
- \( 5 \times 5 = 25 \)
- \( 25 \times 5 = 125 \)
- \( 125 \times 5 = 625 \)
Practice regularly with different numbers to strengthen your skill in evaluating exponents, and you'll find it becomes second nature over time.