Question

when solving for a domain and range of a function, when does one know when to use a sign chart?

Answer 1

when explaining it to the deaf?

Answer 2

what is a sign chart?

Answer 3

As far as I know, you use it when there's a radical present w/ factors in it. so basically, you have to make sure those radicals are greater than or equal to zero, hence the use of the sign chart. HAHA. I think it's used for domain mostly, though.