F(X) Questions

Question

Simplify and determine the domain.

 

f(x)=9x-8/81x² -64 

Answer 1

OK, I think this is what you mean:

 

(9x - 8)/(81 x^2 - 64)

 

So, factor the denominator:

 

(9x - 8)/(9x - 8) (9x + 8)

 

cancel like terms

 

1/(9x + 8) = f(x)

 

The domain is all real numbers except -8/9, because using that for x yields a denominator of zero, which is undefined.