fINDING THE DOMAIN OF A FUNCTION

[carlyn]

I have f(x)= x^2 +5x +6

find the domain , all possible values of x

so f(x) = x^2 + 5x +6 factors out to (x+3) (x+2)

Imy anser is x is all rational numbers except -3 or -2

BexSE if i tried x = -3 0r x = -2 then the sum would be 0

Im told that the answer could be -3 or -2 in my notes ? How can this be please sir ?

Carlyn.

 

[iceybloop]

The function's value can be zero. It just can't be undefined. Is there anything you can substitute for x that wouldn't yield some value for f?

Also, why rational numbers?

 

[ameri]

-2 and -3 are answers of the equation not the domain.
The domain of this function is R. (all real numbers)