what is the axis of symmetry for the graph of y=2x^2-8x+2

Question

anonymous · Answer

attachment

ahsome · Answer

The equation for the axis of symatry is:
$$x=\frac{-b}{2a}$$
That should help

ahsome · Answer

For your equation:
$a=2$
$b=-8$

Simply sub the values into the equation:

$$x=\frac{-b}{2a}$$$$x=\frac{-1*2}{2*-8}$$Go from there :)

ahsome · Answer

Does that make sense, @HugoHuynh ?

anonymous · Answer

so what is the answer

ahsome · Answer

What is:
$$\frac{-2}{-16}$$

anonymous · Answer

0.125

ahsome · Answer

Thats it :)

ahsome · Answer

Hope that helps @HugoHuynh :)

anonymous · Answer

You can also do this by completing the square method

ahsome · Answer

Yes, but wouldn't take much longer @KissMyAxe?

Another way is to add up the two $\text{x-intercepts}$, and divide them by $2$

zzr0ck3r · Answer

You actually do this while completing the square :)

ahsome · Answer

@zzr0ck3r, really?
Which one? The formula or adding the $\color{red}{x-intercepts}$ and dividing by $\color{blue}{2}$?

anonymous · Answer

does it give the same answer as 0.125

zzr0ck3r · Answer

@ahsome start with general equation $ax^2+bx+c=0$ and derive the general solutions $x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$ by way of completing the square.

 It's good clean fun and you will see what I mean.

ahsome · Answer

Yah. Did that. the $\sqrt{b^2-4ac}$ tells you how many $\color{blue}{x-intercepts}$ there are, while the rest $(\frac{-b}{2a})$, tells you the $\color{purple}{\text{Axis of Symatry}}$, @zzr0ck3r :)

zzr0ck3r · Answer

:)

ahsome · Answer

$$\begin{bmatrix}
\color{blue}{SO}& \color{red}{PRETTY} \
\color{purple}{\LaTeX}& \color{green}{zzr0ck3r}
\end{bmatrix}$$
@zzr0ck3r