Question 2: Consider the relationship between y=f(x) and y=-f(x)

Part A fill in the blanks (3 points):
What is this type of function transformation called? What does it look like on a graph?
Answer: This type of transformation is called a [blank]. Specifically, it is a reflection over the [blank]-axis. On a graph, this means that every point on the graph of y=-f(x) [blank].
Part B Sketch a graph ( 7 points):
Choose one of the parent functions (. Create a fake graph for both the parent function and the transformation. Be sure to clearly label each sketch.
F(x)= 3√x
F (x) = 2^x
F (x) = x
f(x)= x^2
F (x) = √x

1 answer

Part A: Fill in the Blanks

  1. What is this type of transformation called?

    • Answer: This type of transformation is called a reflection.
  2. What does it look like on a graph?

    • Answer: Specifically, it is a reflection over the x-axis. On a graph, this means that every point on the graph of y = -f(x) is mirrored across the x-axis.

Part B: Sketch a Graph

Let's choose the parent function \( f(x) = x^2 \) for the graph illustrations.

Graph Sketches

Parent Function: \( f(x) = x^2 \)

  1. Description: The graph of \( f(x) = x^2 \) is a parabola that opens upward with its vertex at the origin (0,0).

    • Sketch:
          |
         4|                *
          |              *   *
         3|            *       *
          |          *           *
         2|        *               *
          |      *                   *
         1|    *                       *
          |  *                           *
      ---- +------------------------------ 
          -2 -1  0   1   2   3   4  
    

Transformation: \( g(x) = -x^2 \)

  1. Description: The graph of \( g(x) = -x^2 \) is also a parabola, but it opens downward with its vertex at the origin (0,0).

    • Sketch:
          |
         4|  
          |                                   
         3|               
          |          
         2|             
          |               
         1|              
          |         *                       * 
      ---- +------------------------------
          -2 -1  0   1   2   3   4  
          |       *                   * 
         -1|         *               *
          |           *           *
         -2|             *       *
          |               *
         -3|                *
          |                  
         -4|                  
    

Labeling

  • Curve for \( f(x) = x^2 \): Label this curve as "Parent Function: \( f(x) = x^2 \)".
  • Curve for \( g(x) = -x^2 \): Label this curve as "Transformation: \( g(x) = -x^2 \)".

Conclusion

The sketches show the effect of reflecting the parent function \( f(x) = x^2 \) across the x-axis to create the function \( g(x) = -x^2 \).