Consider the relationship between y = f(x) and y = f(x) +/= k.

What is this type of function transformation called? What does it look like on a graph?

1 answer

The transformation you are describing, where you have \( y = f(x) \) and then modify it to \( y = f(x) \pm k \), is known as a vertical shift or vertical translation.

Explanation:

  • Vertical Shift: When you add or subtract a constant \( k \) from the function \( f(x) \), you are effectively shifting the entire graph of the function vertically.
    • If \( k > 0 \): The graph shifts upward by \( k \) units. For example, if the original function is \( y = f(x) \) and you change it to \( y = f(x) + k \), the entire graph moves up.
    • If \( k < 0 \): The graph shifts downward by \( |k| \) units. For instance, changing \( y = f(x) \) to \( y = f(x) - k \) would move the graph down.

Graphical Representation:

  • If you take a simple function, such as \( f(x) = x^2 \), the graph of \( y = x^2 \) is a parabola opening upwards.
    • If you transform it to \( y = x^2 + 2 \), the vertex of the parabola moves from (0, 0) to (0, 2).
    • Conversely, if you transform it to \( y = x^2 - 2 \), the vertex moves to (0, -2).

In summary, the transformations \( y = f(x) + k \) and \( y = f(x) - k \) result in vertical shifts of the graph of \( f(x) \), either upwards or downwards depending on the sign of \( k \).