We can look at the graph
Vertex:
we know that vertex is the point where parabola changes it's shape
we can see that
vertex is at (0.5,-0.75)
Axis of symmetry:
we know that axis of symmetry of parabola is always x-value of vertex
we can see that
x-value of vertex is 0.5
so, axis of symmetry is
[tex] x=0.5 [/tex]
Formula for the function:
we know that this is graph of parabolas
so, we can use vertex formula of parabola
[tex] y=a(x-h)^2+k [/tex]
where
(h,k) is vertex
Here , we got
vertex as (0.5 , -0.75)
h=0.5 and k=-0.75
now, we can plug these values
[tex] y=a(x-0.5)^2-0.75 [/tex]
now, we need to find 'a'
we can select any one point of parabola
and then we can find 'a'
We can see that one of point is (0,-1)
so, we can plug x=0 and y=-1
[tex] -1=a(0-0.5)^2-0.75 [/tex]
[tex] -0.25=a(0-0.5)^2 [/tex]
[tex] -0.25=0.25a [/tex]
[tex] a=-1 [/tex]
now, we can plug it back
and we get
[tex] y=-1(x-0.5)^2-0.75 [/tex]
now, we can expand it
[tex] y=-x^2+x-0.25-0.75 [/tex]
[tex] y=-x^2+x-1 [/tex]
so, option-D..........Answer