What is the domain of f (x) = 1/x-3

The domain is all real numbers except x=3

Step-by-step explanation:

Assuming you mean

f (x) = 1 / (x-3)

The domain is all numbers that x can take

This function is define except when the denominator goes to zero

x-3 cannot be zero

x cannot be 3

The domain is all real numbers except x=3