Final answer:
The statements can be logically expressed using universal quantifiers and implications. A step-by-step logical proof demonstrates the validity of the conclusion using rules of inference. Part B involves evaluating a function, and Part D solves a geometric recurrence relation.
Step-by-step explanation:
To express the given statements logically:
- №1: ∀x(P(x) → S(x)) - 'All hummingbirds are richly colored.'
- №2: ∀x(Q(x) → ¬R(x)) - 'No large birds live on honey.'
- №3: ∀x(¬R(x) → ¬S(x)) - 'Birds that do not live on honey are dull in color.'
- №4: ∀x(P(x) → ¬Q(x)) - 'Hummingbirds are small.'
Using rules of inference, we can show that the last statement is a valid conclusion:
- From №2 and №3, we apply hypothetical syllogism to get: ∀x(Q(x) → ¬S(x)).
- From №4, we know that if x is a hummingbird, then x is not large, hence if P(x) then ¬Q(x).
- Then by modus ponens, from №1, if P(x) then S(x) (hummingbirds are richly colored).
- Therefore, combining the results, we deduce that hummingbirds being small (¬Q(x)) and also richly colored (S(x)) is a valid conclusion given the premises.
For part b), the function is g(x) = x - 3. If x > 0, then g(x) > -3 since we subtract 3 from a positive number.
For part d), the solution to the recurrence relation an = 2.7an-1 with initial condition a1 = 1 is given by a geometric sequence where each term is 2.7 times the previous term.