For the equation:
#y=sqrt(x+2)#
we can graph this starting with an understanding of the graph, #sqrtx# and adjusting from there. Let's take a look at that graph first:
graph{sqrtx [-1, 10, -3, 5]}
The graph of #sqrtx# starts at #x=0, y=0# (since we're graphing in real numbers on the x and y axis, the value under the square root sign can't be negative) then passes through #x=1, y=1# and #x=4, y=2# and will head off to infinity.
So how do we now graph #sqrt(x+2)#? What will make the value under the square root sign equal 0? #x=-2#. And so the we'll have the same shape of graph, but moved 2 places to the left. It'll look like this:
graph{sqrt(x+2) [-3, 10, -3, 5]}