1) Given that we have the vertex at (1,1) and one point (2,6) then we can write
y=a(x-h)²+k
So we can see that this parabola is a<0 due to its point (2, -6)
h = -b/2a = 1
k= -Δ/4a = 1
y=a(x-h)²+k
y=-a(x-1)²+1
2) Let's find the "a" plugging points (2,-6) and (1,1) into the formula:
y=a(x-h)²+k
-6 =a(2-1)² +1
-6= a(1) +1
-6-1=a
a=-7
3) So now we can write our equation:
y= -7(x-1)²+1