What is the vertex form of $y= 3x^2 + 9x-6$ ?

Question

3124 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-03-02T12:59:01

$3(x-3/2)^2-51/4$

The vertex form of the quadratic expression $ax^2+bx+c$ is $a(x-h)^2+k$ .

We have $3x^2+9x-6$

Or:

$3(x^2+3x)-6$

To complete the square, we take the coefficient of $3x$ , divide it by $2$ , square it and add it:

$3(x^2+3x+9/4)-6-27/4$

$3(x-3/2)^2-51/4$

So the vertex is, incidentally, $(3/2,-51/4)$

What is the vertex form of y= 3x^2 + 9x-6y= 3x^2 + 9x-6?