Question

PLEASE HELP!!!

f(x) = x^2 + 4x − 1 in vertex form

Answer 1

@Nurali

Answer 2

hint: you want to use completing the square ^_^

Answer 3

I don't know how to do that.

Answer 4

So now you want to plug b = 4 into the formula:
\[(\frac{ b }{ 2})^{2} \]
\[= (\frac{ 4}{ 2 }) ^2 = 2^2 = 4 \]
Therefore to complete the square we have to add 4
\[f(x) = x^2 + 4x - 1 \]
\[= (x^2 + 4x + 4) - 1 \]
\[= (x + 2)^2 -1\]