we have
f(x)=(1/2)(x-1)^2+3
this is a vertical parabola open upward
the vertex is a minimum
the vertex is the point (1,3)
the axis of symmetry of a vertical parabola is equal to the x-coordinate of the vertex
so
the axis of symmetry is x=1
The domain of any parabola is all real numbers
Domain (-infinire, infinite)
The range is the interval {3, infinite)
The function is increasing at the interval (1, infinite)
The function is decreasing at the interval (-infinite, 1)
see the attached figure to better understand the problem
please wait a minute