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)
Ch. 4 - Exponential and Logarithmic Functions

5장, 문제 84
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?
검증된 단계별 안내1
Identify the formula for continuous compounding: \( A = P e^{rt} \), where \( A \) is the future value, \( P \) is the principal, \( r \) is the annual interest rate (in decimal form), \( t \) is the time in years, and \( e \) is the base of the natural logarithm.
Substitute the known values into the formula: \( A = 3P \) (since the value triples), \( P = 50000 \), and \( r = 0.075 \). The equation becomes \( 3(50000) = 50000 e^{0.075t} \).
Simplify the equation by dividing both sides by \( 50000 \): \( 3 = e^{0.075t} \).
Take the natural logarithm (\( \ln \)) of both sides to isolate \( t \): \( \ln(3) = 0.075t \).
Solve for \( t \) by dividing both sides by \( 0.075 \): \( t = \frac{\ln(3)}{0.075} \). This will give the time in years to the nearest tenth.

비슷한 문제에 대한 검증된 영상 답변:
이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
4m도움이 되었나요?
주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
Continuous Compounding
Continuous compounding refers to the process of earning interest on an investment at every possible moment, rather than at discrete intervals. The formula used for continuous compounding is A = Pe^(rt), where A is the amount of money accumulated after time t, P is the principal amount, r is the annual interest rate, and e is the base of the natural logarithm. This method allows for the maximum growth of an investment over time.
추천 영상:
The Number e
Exponential Growth
Exponential growth occurs when the growth rate of a value is proportional to its current value, leading to rapid increases over time. In the context of finance, this is often modeled using the exponential function, which reflects how investments grow when interest is compounded continuously. Understanding this concept is crucial for predicting how long it will take for an investment to reach a certain value.
추천 영상:
Exponential Functions
Natural Logarithm
The natural logarithm, denoted as ln, is the logarithm to the base e (approximately 2.71828). It is particularly useful in solving equations involving exponential growth, such as those found in continuous compounding. When determining the time required for an investment to grow to a specific amount, the natural logarithm helps isolate the variable t in the continuous compounding formula.
추천 영상:
The Natural Log
관련 실천
교과서 질문
1283
views
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)
819
views
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 8
894
views
교과서 질문
Evaluate or simplify each expression without using a calculator. 10log 33
894
views
교과서 질문
Evaluate or simplify each expression without using a calculator. log 107
885
views
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. 2 log x−log 7=log 112
814
views
