we have the function
f(x)=3x^2-54x+241
this is a vertical parabola open upward (because the leading coefficient is positive)
the vertex is a minimum
Convert the quadratic equation into vertex form
y=a(x-h)^2+k
where
(h,k) is the vertex
and the axis of symmetry is equal to the x-coordinate of the vertex
so
x=h
step 1
Factor the leading coefficient
the vertex is the point (9,-2)
the axis of symmetry is x=9
the vertex represent a minimum