Given f(x) = x / (x^2 - 4), find and simplify f (3x).

Question

kj4uts · Answer

Are they asking me to plug 3(x) into the equation like this 3x / (3x^2 - 4)? If that is the case I do not think it can be simplified anymore.

xmissalycatx · Answer

Let's see..

kittiwitti1 · Answer

$$f(x)=\frac{x}{x^{2}-4}\rightarrow f(3x)=\frac{3x}{(3x)^{2}-4}=\frac{3x}{9x^{2}-4}$$

kj4uts · Answer

Oh I see so you square the 3^2 to get the 9 on the bottom?

kittiwitti1 · Answer

$$\rightarrow\frac{3x}{9x^{2}-4}\rightarrow\frac{3x}{(3x-2)(3x+2)}$$

xmissalycatx · Answer

I was drawing it out, but every time I'm about to send what I'm drawing @kittiwitti1 sends those equations XD poop

kittiwitti1 · Answer

Well... if you don't put it in the equation properly you end up getting$$3x^{2}\text{ which is basically like }3\times x^{2}$$But what we're looking for here is$$(3x)^{2}\text{ as you're putting } "3x"\text{ into the place of }x$$LOL sorry xD

kittiwitti1 · Answer

It's asking you to simplify, you don't need to reverse the process and re-multiply... I just factored it out for you. Lol

kj4uts · Answer

Thank you for your time and help :)

kittiwitti1 · Answer

No problem ^-^

kittiwitti1 · Answer

By the way, if you get confused there is always WolframAlpha to check your problems with~ http://www.wolframalpha.com/input/?i=f(x)+%3D+x+%2F+(x%5E2+-+4)+when+x%3D3x