Step-by-step explanation: To find the x-value of the vertex for any quadratic, you can use the formula -b/2a. In this case, there is no clear b, but you can think of it like y=-x^2 +0x+3 so in the form ax^2 + bx +c, b=0. Therefore the x-value is 0/ -2, or 0. So we know the vertex is (0, y). To find y, just plug 0 into the original equation for x, getting you y=0+3, so y=3, so the vertex is (0,3)
