Which function's domain consists of all real numbers except 3?

a) f (x) = 3x+3

b) f (x) = 3/x-3

c) f (x) = 3x^2

d) f (x) = 3x-3

e) f (x) = 1 / square root of x-3,

The answer is e. To determine the domain you must first find all possible x-values that allow a function to work resulting in real y-values. The bottom number of a fraction can never be 0. In all other options 3 is one of the real numbers.