What does reflection in the y-axis mean in coordinate geometry?
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It is a transformation that maps each point (x, y) to (-x, y), flipping the x-coordinate while keeping the y-coordinate unchanged.
How do you reflect a point over the y-axis?
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To reflect a point (x, y), change its x-coordinate to -x, resulting in the point (-x, y).
What happens to the sign of the x-value during a y-axis reflection?
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The sign of the x-value is inverted; a positive becomes negative and vice versa.
Is the y-axis itself affected by a reflection over itself?
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No, points on the y-axis remain unchanged because their x-coordinate is zero.
Can you give an example of reflecting a shape over the y-axis?
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Reflecting the triangle with vertices (1,2), (3,4), (5,2) produces vertices (-1,2), (-3,4), (-5,2).
Does reflection in the y-axis preserve distances between points?
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Yes, it preserves distances because it is an isometry.
What is the effect of reflecting the line y = mx + b over the y-axis?
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The reflected line becomes y = m(-x) + b, or y = -mx + b.
Why is reflection over the y-axis considered a linear transformation?
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It can be represented by a matrix multiplication without translation, satisfying linearity properties.
Are reflections in the y-axis orientation-reversing?
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Yes, they reverse the orientation of figures like clockwise becomes counterclockwise.
How does reflection affect the symmetry of a graph?
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If a graph is symmetric about the y-axis, it remains unchanged after such a reflection.