You can do it this way :
- graph y=x². (I guess you know how to do it... ?)
- graph y=(x-2)² by translating the graph of x² of two units to the right (because x becomes x-2)
- graph y=-1/3*(x-2)² : multiplying by a constant. So the general appearance won't change, but because it's a negative constant, all the positive y will become negative, though the absolute value stays still. It's a symmetry to the x axis.
- graph y=-1/3*(x-2)²+1 : add 1 to the y, that is to say "elevate the curve of 1 unit"
Does it look clear to you ?