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Algebra and Trigonometry Study Guide

Unit 1 · Core unit

Functions, Transformations, and Inverses

Function notation, domain and range, and the transformations that move any graph. Learned once, this unit applies to every family that follows.

What a strong answer looks like

A strong answer applies inside changes in the opposite direction to their sign, and states domain restrictions explicitly.

Topics in this unit

1

Function Notation, Domain, and Range

Know

Function notation names an output for an input. Division, even roots, and logarithms each remove values from a domain.

Apply

Find a domain by excluding what breaks the expression, then read the range from the resulting shape.

Watch out

Treating function notation as multiplication.

Study move

State the domain of a rational, a radical, and a logarithmic expression.

2

Transformations

Know

Changes inside the function act horizontally and opposite to their sign; changes outside act vertically as written.

Apply

Decompose into steps and apply them to a known point, working inside changes backwards.

Watch out

Reading a horizontal compression as a stretch, or a shift in the wrong direction.

Study move

Track one point through a transformation with a reflection, a compression, and two shifts.

3

Composition and Inverses

Know

Composition feeds one output into another function, and the domain inherits both restrictions. An inverse exists only where a function is one-to-one.

Apply

Find an inverse by exchanging input and output roles and solving; restrict the domain first if needed.

Watch out

Claiming an inverse exists for a function that fails the horizontal line test.

Study move

Find the domain of a composition where the inner function restricts the outer.

Emphasized in this unit

  • Excluding domain values before anything else
  • Working inside transformations backwards
  • Checking one-to-one before inverting

Varies by course

  • Piecewise functions. Depth varies by course.
  • Even and odd symmetry. Introduced at different points.

Mastery checklist

  • State a domain from a formula.
  • Apply a composite transformation to a point.
  • Find an inverse and state any needed restriction.

Check yourself

  • Why do inside changes act in the opposite direction?
  • Why must some functions be restricted before inverting?

Modeling drill

Given a point on a graph, find the corresponding point after a reflection, a horizontal compression, and a vertical shift.

Function notationDomainRangeTransformationCompositionInverseOne-to-one