When the value of k increases, the graph of the function shifts up.
When the value of k decreases, the graph of the function shifts down.
<h3>What is a translation?</h3>
A translation is represented by a change in the function graph, according to operations such as multiplication or sum/subtraction either in it’s definition or in it’s domain. Examples are shift left/right or bottom/up, vertical or horizontal stretching or compression, and reflections over the x-axis or the y-axis.
The translation y -> y + k represents:
A shift up if k > 0.
A shift down if k < 0.
Hence:
When the value of k increases, the graph of the function shifts up.
When the value of k decreases, the graph of the function shifts down.