I assume you mean f(x)= (x+1)2- 1. First you should know that this is a parabola(the U looking graph), because it has the square. When graphing parabolas, it is
all about the vertex. I cannot stress that enough, If you know the vertex, the rest is easy-peasy.
In a problem set up like this we call this form, Vertex Form because it basically spells it out for you. The vertex here is (-1, -1). Where did we get this? (-1, ) this number came from the parentheses. What number goes in the parentheses for x that
will make the parentheses value 0? (-1+1) = 0, the is where (-1, ) came from. (many people think of it as the opposite of the number inside the parentheses)
( , -1) came from the constant number at the end ( )2 - 1
So now that we have the vertex, we can make an x y chart, and pick values for x and plug in to find y.
what I tell my students is put your vertex in the middle of the chart and pick 2 values below and 2 values above.
After plugging the following values in -3, -2, 0 and 1 and create the ordered pairs and graph them. It should look like the classic U shape but the vertex is located one unit left and one unit down from the origin.
One other example: if f(x) = (x - 4)2 + 7, then the vertex would be (4, 7) and our chart would look like
Hope this helps, if any of the explanation is unclear, let me know.
(P.S. f(x) can be treated as y)