When a shape on a graph is u shape opening upward and another shape that is a transformation that is wider and shifts to the left or right How do you count the units

1 answer

To analyze the transformation of U-shaped graphs (commonly represented by quadratic functions like y=ax2), you need to consider a few aspects: the width of the graph and the horizontal shifts. Here's how to count the units for these transformations:

  1. Normal U-shape: The standard form of a U-shaped graph is y=ax2 where a>0. If a=1, the graph is "normal" in width.

  2. Wider Shape: A wider shape can be represented by y=a(xk)2 where k>1. Here, a still controls the direction of the U (upward or downward) and k affects the width:

    • If k>1, the shape is wider compared to y=ax2.
    • The value of k indicates how many times wider the graph is. For example, if k=2, the graph is twice as wide.
  3. Horizontal Shift: To shift the graph left or right, translate the variable x appropriately. The transformation has the form y=a(xh)2 where:

    • h>0 shifts the graph h units to the right.
    • h<0 (or simply a y=a(x+c)2 style) shifts the graph c units to the left.

Summary Steps to Count Units:

  • Identify the Vertex: In the standard form y=a(xh)2+k, the vertex is at point (h,k).
  • Counting Units:
    • For width, consider the constant k used in y=a(xk)2 (the greater the k value, the wider the graph).
    • For horizontal shifts, look at h:
      • Positive h = shift right by h units.
      • Negative h or the addition of a positive in standard form = shift left by c units.

For practical examples:

  • If the original parabola is y=x2 and the transformation is y=14(x3)2:
    • The graph opens upward, shifts 3 units to the right, and the 14 makes it wider than the original.

Remember, carefully analyze each term in the equation to count shifts and width correctly!