๐ŸŽฏโญ INTERACTIVE LESSON

Functions

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Functions - Complete Interactive Lesson

Part 1: Function Notation

๐Ÿ“ Functions Graphs

Part 1 of 7 โ€” Function Notation & Evaluation

f(x) means "the output of function f when the input is x".

To evaluate f(3): substitute 3 everywhere you see x.

Check Your Understanding ๐ŸŽฏ

Key Insight: f(a) = 0 means a is a zero (x-intercept) of the function.

SAT Tip: If f(x) = 2x + 1, then f(3) = 2(3) + 1 = 7.

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Part 2: Interpreting Graphs

Domain and Range

Part 2 of 7 โ€” Domain and Range

Domain: all possible input (x) values.

Range: all possible output (y) values.

Check Your Understanding ๐ŸŽฏ

Key Insight: Restrictions: no division by zero, no square root of negatives (for reals).

SAT Tip: From a graph: domain is the horizontal extent, range is the vertical extent.

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Part 3: Domain & Range

Interpreting Graphs

Part 3 of 7 โ€” Interpreting Graphs

Increasing: graph goes up left to right; decreasing: goes down.

Maximum/minimum: highest/lowest point on the graph.

Check Your Understanding ๐ŸŽฏ

Key Insight: Intercepts: where the graph crosses the axes.

SAT Tip: Rate of change = (change in y)/(change in x) = slope between two points.

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Part 4: Transformations

Transformations of Functions

Part 4 of 7 โ€” Transformations of Functions

f(x) + k: shifts up k units; f(x) - k: shifts down k.

f(x - h): shifts right h units; f(x + h): shifts left h.

Check Your Understanding ๐ŸŽฏ

Key Insight: af(x): vertical stretch (a > 1) or compression (0 < a < 1).

SAT Tip: f(-x): reflects over y-axis; -f(x): reflects over x-axis.

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Part 5: Function Composition

Function Composition

Part 5 of 7 โ€” Function Composition

(f โˆ˜ g)(x) = f(g(x)): apply g first, then f.

Find g(x) first, then use that result as input to f.

Check Your Understanding ๐ŸŽฏ

Key Insight: Domain of f โˆ˜ g: x must be in domain of g, AND g(x) must be in domain of f.

SAT Tip: Example: f(x) = xยฒ, g(x) = x + 1, then f(g(x)) = (x+1)ยฒ.

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Part 6: Problem-Solving Workshop

Problem-Solving Workshop

Part 6 of 7 โ€” Problem-Solving Workshop

(f โˆ˜ g)(x) = f(g(x)): apply g first, then f.

Find g(x) first, then use that result as input to f.

Check Your Understanding ๐ŸŽฏ

Key Insight: Domain of f โˆ˜ g: x must be in domain of g, AND g(x) must be in domain of f.

SAT Tip: Example: f(x) = xยฒ, g(x) = x + 1, then f(g(x)) = (x+1)ยฒ.

Check Your Understanding ๐ŸŽฏ

Match the Concepts ๐Ÿ”

Part 7: Review & Applications

Review & Applications

Part 7 of 7 โ€” Review & Applications

(f โˆ˜ g)(x) = f(g(x)): apply g first, then f.

Find g(x) first, then use that result as input to f.

Check Your Understanding ๐ŸŽฏ

Key Insight: Domain of f โˆ˜ g: x must be in domain of g, AND g(x) must be in domain of f.

SAT Tip: Example: f(x) = xยฒ, g(x) = x + 1, then f(g(x)) = (x+1)ยฒ.

Check Your Understanding ๐ŸŽฏ

Match the Concepts ๐Ÿ”