What is the vertex of the parabola given by the equation y = x2 + 4?

The vertex of the parabola is (0,4), because you can use - b/2a to find the x coordinate a of the vertex. There is no b so b=0 and 0/anything is 0. Then you can plug 0 into the equation to find the y coordinate of the vertex. When you plug in 0 you get 4, so the vertex is (0,4)