# Math Help - Homework Help Needed Topic: Funcions

1. ## Homework Help Needed Topic: Funcions

Hey I'm currently doing Functions in Maths. I am from London and you may use different terminology for this topic. I do not understand a certain question, can anyone help please?

If f(x) = 1/x2 (x squared) find, 1/f(x), f(1/x) and 1/f(1/x)

2. $f(x) = \frac{1}{x^2}$

$\frac{1}{f(x)} = \frac{1}{(\frac{1}{x^2})} = x^2$

$f(\frac{1}{x}) = \frac{1}{(\frac{1}{x})^2} = \frac{1}{(\frac{1}{x^2})} = x^2$

$\frac{1}{f(\frac{1}{x})} = \frac{1}{x^2}$

Do you understand or should I elaborate more?

For the first one at least you should know that:
$\frac{a}{(\frac{b}{c})} = \frac{ac}{b}$

Note the difference with this:
$\frac{(\frac{a}{b})}{c} = \frac{a}{bc}$

3. Hello,

When you have something like f(a), replace x by a in the formula f(x).

So f(a)=1/a² when f(x)=1/x²