# How do you find all the zeros of #f(x)=x^3 -8x^2 -23x +30#?

##### 1 Answer

#### Answer:

They are

#### Explanation:

To solve a cubic equation it exists the solving formula but it is very long and I do not know it.

Then I use a bit of luck to solve this equation. For example I see that

Then I know that the equation has to be in the form

To find

Comparing this with our initial equation we see that

Our function is then

Now we have to solve a second order equation

that has the two solutions

Then the function

can be rewritten as