Question

Write in vertex form

Answer 1

• Vertex form: $y=a(x-h)^2+k$

So firstly, put x^2 - 4x into parentheses: $y=(x^2-4x)+6$

Next, we need a perfect square inside the parentheses. Divide the x coefficent by 2 then square that result. In this case, -4 ÷ 2 = -2, (-2)²= 4. Add 4 inside the parentheses and then subtract 4 outside the parentheses:

$y=(x^2-4x+4)+6-4\\y=(x^2-4x+4)+2$

Lastly, factor what's inside the parentheses and your vertex form is $y=(x-2)^2+2$