THE BIG IDEA
Logarithms
How long does repeated growth take?
Exponents describe repeated multiplication. Logarithms reverse the question: which exponent produces a target? Keeping that inverse relationship in view makes the algebraic rules less arbitrary.
SEE THE CONNECTIONS
How the ideas fit together.
A map of the main ideas. Follow a node to its lesson.
- Start with01Exponential growth
- asking for the exponent defines02Logarithms
- multiplying growth factors explains03Combining logs
- comparing scales leads to04Change of base
YOUR LEARNING ROUTE
One idea at a time.
Read the explanation, use the visualization, then try the check before opening its reasoning.
Keep the unit cheat sheet handy →Exponential Functions2 lessons
Definition and Basic Concepts4 lessons
- 03Defining the LogarithmTranslate a logarithm into an exponential equation.Marked studied
- 04The Inverse of an Exponential FunctionConnect exponential growth with its logarithmic inverse.Marked studied
- 05The Inverse of a Logarithmic FunctionRecover an exponential function from a logarithm.Marked studied
- 06Conditions on the Base and the ArgumentCheck base and argument restrictions before applying log rules.Marked studied
The Rules8 lessons
- 07The Four Basic RulesUse the basic inverse identities of exponents and logarithms.Marked studied
- 08When the Base Is Not WrittenIdentify a logarithm’s base from the stated convention.Marked studied
- 09The Natural LogarithmUse natural logarithms to undo exponentials with base e.Marked studied
- 10The Product RuleCombine sums of logarithms using the product rule.Marked studied
- 11The Quotient RuleCombine differences of logarithms using the quotient rule.Marked studied
- 12Swapping the Base and the ExponentExplain why a base and logarithmic exponent can exchange roles.Marked studied
- 13When a Logarithm Is the ExponentSimplify exponentials containing a matching logarithm.Marked studied
- 14Changing the BaseChange a logarithm to a convenient base.Marked studied