📘intermediate algebra review

Log₁₀

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

The logarithm to the base 10, denoted as log₁₀, is a mathematical function that represents the power to which a base of 10 must be raised to obtain a given number. It is a fundamental concept in the context of using the properties of logarithms to solve various mathematical problems.

5 Must Know Facts For Your Next Test

  1. The logarithm to the base 10, log₁₀, is used to represent very large or very small numbers in a more compact form.
  2. The value of log₁₀(x) represents the power to which 10 must be raised to get the number x.
  3. Logarithms to the base 10 are useful in various mathematical and scientific applications, such as in the measurement of earthquake magnitudes and sound intensity levels.
  4. The properties of logarithms, such as the product rule, power rule, and logarithm of a quotient, are important in simplifying and solving equations involving logarithms.
  5. Logarithms to the base 10 are closely related to the concept of exponential functions, as they represent the inverse operation of exponentiation.

Review Questions

  • Explain the relationship between log₁₀ and the base 10 exponential function.
    • The logarithm to the base 10, log₁₀, is the inverse operation of the base 10 exponential function. If we have an exponential equation in the form $10^x = y$, then the logarithm to the base 10 of $y$ is equal to $x$. This means that log₁₀(y) = x, where $x$ is the power to which 10 must be raised to get the number $y$. This inverse relationship between logarithms and exponential functions is a key property that allows us to solve equations and simplify expressions involving logarithms.
  • Describe how log₁₀ is used to represent very large or very small numbers in a more compact form.
    • Logarithms to the base 10 are useful for representing very large or very small numbers in a more compact and manageable form. For example, the number $1,000,000,000$ can be written as $10^9$, where the logarithm to the base 10 of $1,000,000,000$ is 9. Similarly, the number $0.000001$ can be written as $10^{-6}$, where the logarithm to the base 10 of $0.000001$ is $-6$. This compact representation of numbers using logarithms is particularly useful in scientific and technological applications, where dealing with very large or very small quantities is common.
  • Explain how the properties of logarithms, such as the product rule, power rule, and logarithm of a quotient, are applied in the context of solving equations and simplifying expressions involving log₁₀.
    • The properties of logarithms, including the product rule ($\log_b(xy) = \log_b(x) + \log_b(y)$), the power rule ($\log_b(x^n) = n\log_b(x)$), and the logarithm of a quotient ($\log_b(x/y) = \log_b(x) - \log_b(y)$), are essential in the context of using the properties of logarithms to solve equations and simplify expressions. These properties allow us to manipulate and transform logarithmic expressions, making it easier to solve for unknown variables, simplify complex logarithmic expressions, and apply logarithms in various mathematical and scientific applications. Understanding and applying these properties of logarithms, particularly log₁₀, is crucial for success in the topic of using the properties of logarithms.