Law of Logarithms

Law of Logarithms

Laws of Logarithms

  • Logarithmic Principle: Understand that the logarithm is the reversal of exponentiation.
  • Base of Logarithms: Calculate logarithms with bases other than 10 or e. Remember the change of base rule: log_b(a) = log_c(a) / log_c(b).

  • Product Rule: Recognize the product rule of logarithms which states: log_b(MN) = log_b(M) + log_b(N). This rule is used when you are multiplying terms with the same base.

  • Quotient Rule: Apply the quotient rule: log_b(M/N) = log_b(M) - log_b(N). This applies when you divide terms with the same base.

  • Power Rule: Utilize the power rule: log_b(M^n) = n * log_b(M). This applies when a term with a base is raised to a power.

  • Logarithms of Powers: Know how to calculate logarithms of powers, using the rule log_b(a^n) = n * log_b(a).

Solving Logarithmic Equations

  • Know that when you have an equation in the form log_b(M) = log_b(N), you can drop the logarithms, resulting in M = N.

  • Understand that logarithms can be converted to exponential form to solve the equation.

  • Use properties of logarithms to condense or expand the equation, making it easier to solve.

  • Change of Base Rule: Know how to convert from one base to another to solve logarithmic equations, using the rule: log_b(a) = log_c(a) / log_c(b), where c is the new base.

Applications of Logarithms

  • Understand how logarithms can be used to solve exponential equations.

  • Be aware of real-life applications such as calculating earthquake intensity using the Richter scale, computing sound intensity using decibels, and modelling population growth or decay in biology.

  • Understand how logarithmic scales can be used to represent data that covers a large range of values in a more digestible format.