Respuesta :

THE PARABOLA OPENS DOWN (WHICH IS MAXIMUM ) AND X=1/2
in the form y=ax^2+bx+c
the axis of symmetry is x=-b/2a

so

y=-1x^2+1x+3
b=1
a=-1

line of symmetry is x=-1/(2*-1)=-1/-2=1/2

the axis of symmetry is x=1/2