Question

What is the vertex of the graph of the function below? y = x2 - 4x + 3

Answer 1

The vertex of this function is (2 , -1)

Answer 2

Here's a nice hack

if you have $y=ax^2+bx+c$
the x value of the vertex is $\frac{-b}{2a}$

fo if we have
$y=1x^2-4x+3$
b=-4
a=1

the x value of the vertex is
$\frac{-(-4)}{2(1)}=\frac{4}{2}=2$
subsitutie that for x to find y value

$y=1(2)^2-4(2)+3$
$y=1(4)-8+3$
$y=4-5$
y=-1


the vertex is (2,-1)