# How do you find the domain for f(x)=9/x?

Sep 25, 2016

$\text{The Domain of } f = \mathbb{R} - \left\{0\right)$.

#### Explanation:

As per the Defn. of $f$, we are supposed to to divide the no $9$ by

a variable no. $x$.

Since, we can not divide by the no. $0$, we must have, $x \ne 0$.

In other words, this means that to make $f$ mathematically

meaningful , we can assign to $x$ any value from the Set RR,

except , the no. $0$.

Such a Set becomes the Domain of a given Function, so,

$\text{The Domain of } f = \mathbb{R} - \left\{0\right)$.