Solve each logarithmic equation in Exercises 49–92. Be sure to reject any value of x that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. 2 log x=log 25
Ch. 4 - Exponential and Logarithmic Functions

5장, 문제 83
Evaluate or simplify each expression without using a calculator. log 107
검증된 단계별 안내1
Recall the definition of logarithms: \(\log_b(a)\) asks the question, "To what power must the base \(b\) be raised to get \(a\)?"
In this problem, the base of the logarithm is 10, and the argument is \$10^7\(, so we are looking for the exponent \)x$ such that \(10^x = 10^7\).
Since the bases on both sides of the equation are the same (base 10), the exponents must be equal. Therefore, \(x = 7\).
Thus, \(\log 10^{7} = 7\) because the logarithm of a power of 10 with base 10 is simply the exponent.
This simplification uses the logarithmic identity: \(\log_b(b^k) = k\) for any positive base \(b \neq 1\) and any real number \(k\).

비슷한 문제에 대한 검증된 영상 답변:
이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
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주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
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 for evaluating logarithmic expressions.
추천 영상:
Logarithms Introduction
Logarithm of a Power
The logarithm of a number raised to an exponent can be simplified using the rule log_b(a^n) = n * log_b(a). This property allows you to bring the exponent in front as a multiplier, simplifying calculations without a calculator.
추천 영상:
Powers of i
Common Logarithms (Base 10)
Common logarithms have base 10, written as log or log_10. Since log_10(10) = 1, powers of 10 simplify easily: log_10(10^n) = n. Recognizing this helps quickly evaluate expressions like log 10^7.
추천 영상:
Graphs of Common Functions
관련 실천
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교과서 질문
Solve each logarithmic equation in Exercises 49–92. Be sure to reject any value of x that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. log(x+4)−log 2=log(5x+1)
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교과서 질문
In Exercises 83–88, let logb 2 = A and logb 3 = C and Write each expression in terms of A and C.
logb (3/2)
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교과서 질문
Use a graphing utility and the change-of-base property to graph each function. y = log2 (x + 2)
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교과서 질문
Use the formula for continuous compounding to solve Exercises 84–85. How long, to the nearest tenth of a year, will it take \$50,000 to triple in value at an annual rate of 7.5% compounded continuously?
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교과서 질문
Expand:
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