# A function problem

#### Darya

##### Junior Member
We have a certain function such that f(13)=1. What interval cannot be a solution to an inequality f(x)>=0?

This may seem like a really simple question to some people in here but I've never had to deal with such problems and therefore don't even know how to start. I'd be thankful for any hints or maybe somebody could tell me what I have to read on to be able to solve this.

#### lev888

##### Senior Member
Not enough information. The only point given satisfies the condition, so we don't know which points don't.

#### Darya

##### Junior Member
Not enough information. The only point given satisfies the condition, so we don't know which points don't.
In the task, they also give you a,b,c,d answers to choose from. a: (-infinity; 15], [-10;8], [12;14], [0;+infinity)

#### Darya

##### Junior Member
Not enough information. The only point given satisfies the condition, so we don't know which points don't.
and that's it

#### lev888

##### Senior Member
In the task, they also give you a,b,c,d answers to choose from. a: (-infinity; 15], [-10;8], [12;14], [0;+infinity)
Why didn't you include this in the first post?
I still don't think we have enough information.

#### HallsofIvy

##### Elite Member
If all we know is that "f(13)= 1" then the only thing we can say about the set of x such that f(x)>= 0 is not true is that it does not include 13. Out of the given possible answers only [-10, 8] does not include 13 but there are infinitely many other answers.

#### Darya

##### Junior Member
If all we know is that "f(13)= 1" then the only thing we can say about the set of x such that f(x)>= 0 is not true is that it does not include 13. Out of the given possible answers only [-10, 8] does not include 13 but there are infinitely many other answers.
oh, then it must be it. Thank you!!