Question

For the function below, state the x-coordinate of the x-intercept that is located to the fight of the origin.


`f(x)=x^3-9x`

Answer 1

x = 3

Explanation:

It should NOT be "fight of the origin", rather "right of the origin".

Now let's move on to solve the question...

The x-intercept is found by setting the function equal to 0. Thus:

0 = x^3 - 9x

Let's solve this using algebra:

`0=x^3-9x\\0=x(x^2-9)\\0=x(x-3)(x+3)`

Hence, x = -3 and x = 3

The coordinate that is to the right of the origin is the positive one, so x = 3 is the x-intercept we are looking for.