Answer:
(-infinity, 1) ∪ (1,3) ∪ (3, +infinity)
Explanation:
Here only the 2nd function, g(x) = x^2 - 4x + 3, affects the domain. Recognizing that division by zero is undefined, we set g(x) = 0 anyway and solve for x: x^2 - 4x + 3 = 0 = (x -3 )(x - 1) = 0. Thus, x cannot have either value 3 or 1. Using this info, we write the domain as follows:
(-infinity, 1) ∪ (1,3) ∪ (3, +infinity). This is Answer #3.