THE BIG IDEA
Functions Review
What does a function tell us—and what can it hide?
A function is an input–output rule with one output per allowed input. Build its vocabulary first, then study graph transformations, composition and reversibility as different ways of using that rule.
SEE THE CONNECTIONS
How the ideas fit together.
A map of the main ideas. Follow a node to its lesson.
- Start with01Inputs & outputs
- plotting the rule reveals02Graph behavior
- chaining rules creates03Composition
- undoing a rule requires04Inverse functions
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 →Read and evaluate functions7 lessons
- 01Defining a FunctionIdentify a function by the uniqueness of each input’s output.Marked studied
- 02Evaluating a FunctionEvaluate a function by substituting its input consistently.Marked studied
- 03Domain, Codomain and RangeDistinguish inputs, declared outputs and attained outputs.Marked studied
- 04What Makes a Rule a FunctionUse the vertical-line test to check a relation.Marked studied
- 05Properties of the RangeRelate the range of a function to its codomain.Marked studied
- 06Reading Domain and Range off a GraphRead domain and range from the horizontal and vertical extent of a graph.Marked studied
- 07Domain and Range of a Rational FunctionFind restrictions on a rational function’s inputs.Marked studied
Recognize function families3 lessons
Read symmetry and transformations6 lessons
- 11Even FunctionsRecognize even functions from algebra and symmetry.Marked studied
- 12Odd FunctionsRecognize odd functions from algebra and origin symmetry.Marked studied
- 13Arithmetic on Even and Odd FunctionsPredict parity when combining even and odd functions.Marked studied
- 14Symmetry of a GraphRead reflected points from a graph’s symmetry.Marked studied
- 15Translating a GraphTranslate graphs by tracking how an input is replaced.Marked studied
- 16Stretching and Compressing a GraphDistinguish vertical scaling from changes to the input.Marked studied
Combine and invert functions9 lessons
- 17Defining CompositionEvaluate a composition in the correct order.Marked studied
- 18Properties of CompositionCheck the order and domain of a composition.Marked studied
- 19One-to-One FunctionsTest whether distinct inputs remain distinguishable by their outputs.Marked studied
- 20Functions That Are Not OntoIdentify codomain values that a function does not reach.Marked studied
- 21Onto FunctionsDetermine whether every declared output is attained.Marked studied
- 22Why One-to-One and Onto MatterExplain how bijections make reversible input–output rules possible.Marked studied
- 23Finding the Inverse of a FunctionFind an inverse by solving for the original input.Marked studied
- 24A Shortcut for the InverseUse an inverse shortcut while retaining its nonzero-slope condition.Marked studied
- 25A Function and Its Inverse on the GraphRelate inverse graphs by reflection across y=x.Marked studied