Question

What is the domain function f (x)= ×-5 over x^2- 9

A. all real number but 9
B. all real numbers but 3 and -3
C. all positive real numbers
D. all real numbers but 5 and 9

Answer 1

Assuming your function looks like this: (x-5)/(x^2 - 9), the numbers that are not "allowed" are the ones that cause the denominator to equal 0. That would be a 3 and a -3, because when you square a 3 and a -3, your result is a 9, and putting a 9 in there makes that denominator 0. So your answer is b