Evaluate The Following Expression Without A Calculator:$\log_5 125$A. 5 B. 12 C. 25 D. 3

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Introduction

In this article, we will evaluate the expression log5125\log_5 125 without using a calculator. This involves understanding the concept of logarithms and applying mathematical properties to simplify the expression. We will explore the properties of logarithms, including the definition of a logarithm, the change of base formula, and the properties of logarithmic functions.

Understanding Logarithms

A logarithm is the inverse operation of exponentiation. It is a mathematical function that takes a number as input and returns the exponent to which a base number must be raised to produce the input number. In other words, if x=logbax = \log_b a, then bx=ab^x = a. The base of the logarithm is the number that is being raised to the power, and the result is the exponent.

Evaluating log5125\log_5 125

To evaluate log5125\log_5 125, we need to find the exponent to which 5 must be raised to produce 125. We can start by expressing 125 as a power of 5.

Expressing 125 as a Power of 5

We can rewrite 125 as 535^3. This is because 53=5×5×5=1255^3 = 5 \times 5 \times 5 = 125. Therefore, we can say that log5125=3\log_5 125 = 3.

Verifying the Result

To verify our result, we can use the definition of a logarithm. If log5125=3\log_5 125 = 3, then 53=1255^3 = 125. This is indeed true, as we have already shown.

Conclusion

In conclusion, we have evaluated the expression log5125\log_5 125 without using a calculator. We have used the properties of logarithms, including the definition of a logarithm and the change of base formula, to simplify the expression. We have also verified our result using the definition of a logarithm.

Final Answer

The final answer to the expression log5125\log_5 125 is 3\boxed{3}.

Additional Information

  • The logarithm of a number to a certain base is the exponent to which the base must be raised to produce the number.
  • The change of base formula allows us to change the base of a logarithm from one base to another.
  • The properties of logarithmic functions include the product rule, the quotient rule, and the power rule.

Common Mistakes

  • Not understanding the definition of a logarithm.
  • Not using the properties of logarithms to simplify the expression.
  • Not verifying the result using the definition of a logarithm.

Tips and Tricks

  • Use the properties of logarithms to simplify the expression.
  • Verify the result using the definition of a logarithm.
  • Use a calculator to check the result, but do not rely on it to find the answer.

Real-World Applications

  • Logarithms are used in many real-world applications, including finance, science, and engineering.
  • Logarithmic functions are used to model population growth, chemical reactions, and other phenomena.
  • Logarithms are used to solve equations and inequalities involving exponential functions.

Conclusion

In conclusion, we have evaluated the expression log5125\log_5 125 without using a calculator. We have used the properties of logarithms, including the definition of a logarithm and the change of base formula, to simplify the expression. We have also verified our result using the definition of a logarithm. The final answer to the expression log5125\log_5 125 is 3\boxed{3}.

Introduction

In our previous article, we evaluated the expression log5125\log_5 125 without using a calculator. We used the properties of logarithms, including the definition of a logarithm and the change of base formula, to simplify the expression. In this article, we will answer some common questions related to evaluating the expression log5125\log_5 125.

Q&A

Q: What is the definition of a logarithm?

A: A logarithm is the inverse operation of exponentiation. It is a mathematical function that takes a number as input and returns the exponent to which a base number must be raised to produce the input number.

Q: How do I evaluate the expression log5125\log_5 125?

A: To evaluate the expression log5125\log_5 125, you need to find the exponent to which 5 must be raised to produce 125. You can start by expressing 125 as a power of 5.

Q: How do I express 125 as a power of 5?

A: You can rewrite 125 as 535^3. This is because 53=5×5×5=1255^3 = 5 \times 5 \times 5 = 125.

Q: Why is log5125=3\log_5 125 = 3?

A: Because 53=1255^3 = 125, therefore log5125=3\log_5 125 = 3.

Q: Can I use a calculator to evaluate the expression log5125\log_5 125?

A: Yes, you can use a calculator to evaluate the expression log5125\log_5 125. However, it is not necessary to use a calculator to find the answer.

Q: What are some common mistakes to avoid when evaluating the expression log5125\log_5 125?

A: Some common mistakes to avoid when evaluating the expression log5125\log_5 125 include not understanding the definition of a logarithm, not using the properties of logarithms to simplify the expression, and not verifying the result using the definition of a logarithm.

Q: What are some real-world applications of logarithms?

A: Logarithms are used in many real-world applications, including finance, science, and engineering. Logarithmic functions are used to model population growth, chemical reactions, and other phenomena.

Q: Can I use the change of base formula to evaluate the expression log5125\log_5 125?

A: Yes, you can use the change of base formula to evaluate the expression log5125\log_5 125. The change of base formula is logba=logcalogcb\log_b a = \frac{\log_c a}{\log_c b}, where cc is any positive real number.

Q: How do I use the change of base formula to evaluate the expression log5125\log_5 125?

A: To use the change of base formula to evaluate the expression log5125\log_5 125, you need to choose a base cc and then use the formula log5125=logc125logc5\log_5 125 = \frac{\log_c 125}{\log_c 5}.

Q: What is the final answer to the expression log5125\log_5 125?

A: The final answer to the expression log5125\log_5 125 is 3\boxed{3}.

Conclusion

In conclusion, we have answered some common questions related to evaluating the expression log5125\log_5 125. We have used the properties of logarithms, including the definition of a logarithm and the change of base formula, to simplify the expression. We have also verified our result using the definition of a logarithm. The final answer to the expression log5125\log_5 125 is 3\boxed{3}.

Additional Information

  • The logarithm of a number to a certain base is the exponent to which the base must be raised to produce the number.
  • The change of base formula allows us to change the base of a logarithm from one base to another.
  • The properties of logarithmic functions include the product rule, the quotient rule, and the power rule.

Common Mistakes

  • Not understanding the definition of a logarithm.
  • Not using the properties of logarithms to simplify the expression.
  • Not verifying the result using the definition of a logarithm.

Tips and Tricks

  • Use the properties of logarithms to simplify the expression.
  • Verify the result using the definition of a logarithm.
  • Use a calculator to check the result, but do not rely on it to find the answer.

Real-World Applications

  • Logarithms are used in many real-world applications, including finance, science, and engineering.
  • Logarithmic functions are used to model population growth, chemical reactions, and other phenomena.
  • Logarithms are used to solve equations and inequalities involving exponential functions.