Question

Let f (x)= x + 18 − 3 x − 15 Choose the correct interval form for the DOMAIN of f and then enter the values for the endpoint(s) in the appropriate answer blanks). Enter DNE in any unused blanks.

Answer 1

The domain of f(x) corresponds to the set of real numbers.

D f(x) ∈ ∀X; D f(x) ∈ R

Explanation:

f(x)=X+18-3X-15

f(x)=-2X+3 (right line with negative slope)

This function exists for all values of X, so the domain corresponds to the set of real numbers.

D f(x) ∈ ∀X; D f(x) ∈ R