Question 21671
to find the vertex just use the equation....
x= (-b)/(2*a) so the first one would be

1. y=x^2-4x+6
x=(4)/(2*1)
x= 2

the rest i am just going to put in the answers 
2. -1
3. 0
4. 0
5. -7/8
6. -1/4
7. 1/2