Question

What is the domain of the function?

x+6
(x-7)(x+5)

all real numbers except 7

all real numbers except 5 and -7

all real numbers except -5 and 7

all real numbers

f(x) =-

A

B

C

D

Answer 1

Denominator (x−7)(x+5)=0 when x=7 or x=−5, so those values are excluded.

Domain: all real numbers except −5 and 7 (choice C), i.e. (-∞, -5) ∪ (-5, 7) ∪ (7, ∞).