Answer
The value of k in the equation $y = k + \sin x $ determines the vertical shift of the graph above the x-axis.
$y = 0 + \sin x $ -> no vertical shift, graph lies across x-axis
$y = 2 + \sin x $ -> 2 units vertical shift, graph lies across $y = 2$
$y = 4 + \sin x $ -> 2 units vertical shift, graph lies across $y = 4$
Work Step by Step
See below graph for reference:
