Find the inverse of f(x) = x^2-4x+3. Is the inverse a function?

lol heres the REAL anwser.

y=x^2-4x+3 ( you have to complete the square here)

y=(x^2-4x+(2)^2-(2)^2)+3
y=(x^2-4x+4-4)+3 Rearrange the brackets to take -4 out

y=(x^2-4x+4)-4+3
y=(x^2-4x+4)-1 Simplify the things in the bracket
y=(x-2)^2-1

Now switch places with x and y

x=(y-2)^2-1 solve for y

x+1=(y-2)^2  square root both sides (square root=Sqrt)

plus/minus Sqrt(x+1)=y-2
y=2 plus/minus Sqrt(x+1) and nope it's not a function