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Chapter 1. Section 1.7 Symmetry & Transformations. Points and Symmetry. Types of Symmetry. Symmetry with respect to the x-axis (x, y) & (x, -y) are reflections across the x-axis y-axis (x, y) & (-x, y) are reflections across the y-axis Origin
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Chapter 1 Section 1.7 Symmetry & Transformations
Types of Symmetry Symmetry with respect to the • x-axis (x, y) & (x, -y) are reflections across the x-axis • y-axis (x, y) & (-x, y) are reflections across the y-axis • Origin (x, y) & (-x, -y) are reflections across the origin
Even and Odd Functions • Even Function: graph is symmetric to the y-axis • Odd Function: graph is symmetric to the origin • Note: Except for the function f(x) = 0, a function can not be both even and odd.
Algebraic Tests of Symmetry/Tests for Even & Odd Functions • f(x) = - f(x) symmetric to x-axis neither even nor odd (replace y with –y) • f(x) = f(-x) symmetric to y-axis even function (replace x with –x) • - f(x) = f(-x) symmetric to origin odd function (replace x with –x and y with –y)
Transformation Rules • EquationHow to obtain the graph For (c > 0) • y = f(x) + c Shift graph y = f(x) up c units • y = f(x) - c Shift graph y = f(x) down c units • y = f(x – c) Shift graph y = f(x) right c units • y = f(x + c) Shift graph y = f(x) left c units
Transformation Rules • EquationHow to obtain the graph • y = -f(x) (c > 0) Reflect graph y = f(x) over x-axis • y = f(-x) (c > 0) Reflect graph y = f(x) over y-axis • y = af(x) (a > 1) Stretch graph y = f(x) vertically by factor of a • y = af(x) (0 < a < 1) Shrink graph y = f(x) vertically by factor of a Multiply y-coordinates of y = f(x) by a