Determine points on the graph y= x^(3/2) - x^(1/2) where the tangent line is parallel to y=x+3.

This question is in the unit of my manual about derivatives, which gives me the idea that I have to somehow use this. I know the slope of y=x+3 is 1, which means the tangent lines of the points on that graph will have a slope of 1, but I don't know how to work backward from there. Any hints as to the process would be helpful. There are no relevant examples in my manual at all.