Answer:
Explanation:
Any side to side movement of a function will be reflected inside a set of parenthesis with the x. For example, if the function was a parabola, the parent graph could be, very simply,

Side to side movement would make the equation look like this:

where h is the x coordinate of the vertex.
Up or down movment would make the equation look like this:
for movement upwards, or
for movement downwards. The k represents the y coordiante of the vertex in this parabola.
Because our function has NO numbers inside the parenthesis with the f(x), but it has a -1 after, we are moving the parent graph of this function, whatever it is, down one from its starting position.