In exercises 18–20, determine whether or not the ivt applies to show that the given function takes on all values between f (a) and f (b) for x ∈ (a, b). if it does not apply, determine any values between f (a) and f (b) that the function does not take on for x ∈ (a, b). 18. f (x) = : x for x < 0 x2 for x ≥