Answer :

So to find the x vertex u have to apply the formula x= -b/2a so it will be
x= -(-4)/2(1)
x= 4/2
x= 2
and to find the y vertex u just substitute the x value into the original equation so it will be
y= (2)^2-4(2)+1
y= 4-8+1
y= -3
so the coordinates of the vertex are (2,-3)
By the method : Completing the square

x²-4x+1=0
x²-4x+1-1=-1
x²-4x = -1
x²-4x+4 = -1+4
(x-2)² = 3
(x-2)²-3=0

x(vertex) 
x-2=0
x=2

y(vertex) = -3

S= (2 , -3)