Reflections of Graphs Flashcards

All 6 cards in this deck

What transformation maps the graph of y=f(x)y=f(x) onto the graph of y=−f(x)y=-f(x)?

A reflection in the xx-axis.
Each point (p,q)(p,q) maps to (p,−q)(p,-q).

What transformation maps the graph of y=f(x)y=f(x) onto the graph of y=f(−x)y=f(-x)?

A reflection in the yy-axis.
Each point (p,q)(p,q) maps to (−p,q)(-p,q).

True or false? The graph of y=f(−x)y=f(-x) is the graph of y=f(x)y=f(x) reflected in the xx-axis.

False. It is a reflection in the yy-axis; y=−f(x)y=-f(x) is the reflection in the xx-axis.

The point (7,2)(7,2) lies on the curve y=f(x)y=f(x). What are the coordinates of the corresponding point on the curve y=f(−x)−3y=f(-x)-3?

(−7,−1)(-7,-1).
Reflection in the yy-axis, then a translation 3 units down.

Graph A has equation y=g(x)y=g(x). Graph B is the reflection of graph A in the yy-axis. Write down an equation of graph B.

y=g(−x)y=g(-x).

The graph of y=sin⁡x∘y=\sin x^\circ is reflected in the xx-axis. Write down an equation of the reflected graph.

y=−sin⁡x∘y=-\sin x^\circ (or equivalently y=sin⁡(−x)∘y=\sin(-x)^\circ).