Ok....let's pick some points and put them into the function to get y.....
To save time.... i'm going to pick some points for x and have WolframAlpha generate the associated y values
You can plot these for yourself to get a rough idea of the graph
sqrt(x + 1) - 2 where
x = {-1, -0.5, 0, 0.5, 1, 1.5, 2, 2.5, 3}
y = {-2, -1.29289, -1, -0.775255, sqrt(2) - 2, -0.418861, sqrt(3) - 2, -0.129171, 0}