# How do you find the domain of #f(x)=(x-3)/(x^2-x-2)#?

##### 1 Answer

#### Explanation:

To find the domain of a rational function, you need to determine all values of

So, set

There are several possibilities to solve a quadratic equation, one of my favourite is "completing the circle":

Try to write the left side of the equation like

We already have the

In order to prevail the equality, the term needs to be added on both sides of the equation, leading us to the following:

Now, we can calculate the root on both sides. Don't forget that the root of

Thus, we can further solve the quadratic equation as follows:

This means that for those two values, the denominator of our function would be

So, the domain of the function are all real numbers except