The equation is a dome shaped parabola due to the -1 coefficient of x2
the vertex 'x' value will be found by -b/2a this will also be the axis of symm
to find the ' y' value of the vertex, put the 'x' value found above and compute 'y'
this 'y' will be the max 'y' value.......range will be (-inf, 'y max value')
domain is all x (-inf,+inf)