Interpret the key features of the graph what type of transformation occurred from the parent function

f(x)= 4x^2
Points (0,0), (-1,4),(1,4),(-2,16) and (2,16)
This is a vertical stretch of the parent function y =x^2 due to the changes in the x-intercept
This is a vertical stretch of the parent function y =x^2 due to the changes in the y-coordinates of each point
A vertical stretch y =x^2 due to changes in the x-coordinates of each point
Vertical stretch y =x^2 due to changes in y-intercept

1 answer

The function given is \( f(x) = 4x^2 \), which is a vertical transformation of the parent function \( y = x^2 \).

Key Features of the Transformation:

  1. Vertical Stretch: The presence of the coefficient \( 4 \) in front of \( x^2 \) indicates a vertical stretch by a factor of \( 4 \). This means that for every \( y \)-value of the parent function \( y = x^2 \), the \( y \)-value of the transformed function \( f(x) = 4x^2 \) is four times greater.

  2. Coordinates Interpretation:

    • The point \( (0, 0) \) remains the same since when \( x=0 \), \( f(0) = 4(0^2) = 0 \).
    • The point \( (-1, 4) \) can be understood by substituting \( x = -1 \): \[ f(-1) = 4(-1)^2 = 4(1) = 4. \]
    • The point \( (1, 4) \) similarly: \[ f(1) = 4(1)^2 = 4(1) = 4. \]
    • The points \( (-2, 16) \) and \( (2, 16) \) are obtained as follows: \[ f(-2) = 4(-2)^2 = 4(4) = 16, \] \[ f(2) = 4(2)^2 = 4(4) = 16. \]

Conclusion on Transformations:

From the above interpretations, we confirm a vertical stretch occurred:

  • This is a vertical stretch of the parent function \( y = x^2 \) due to the changes in the y-coordinates of each point.

This option correctly describes the impact of the factor \( 4 \) on the graph: the \( y \)-values have been stretched upward, while the \( x \)-coordinates remain unchanged in their distance from the \( y \)-axis. Therefore, the correct response to the transformation from the parent function \( y = x^2 \) to \( f(x) = 4x^2 \) is indeed the vertical stretch based on changes in the \( y \)-coordinates.