Question 3 Consider the function f(x) = 3x + 8x . For this function there are four important intervals: (-00, A, [A, B), (B, C), and [C,oo) where A, and Care the critical numbers and the function is not defined at B. Find A and B and C For each of the following open intervals, tell whether f(x) is increasing or decreasing. (-00, A): Increasing V (A, B): Increasing (B, C): Increasing (C,00) Decreasing Note that this function has no inflection points, but we can still consider its concavity. For each of the following intervals, tell whether f(x) is concave up or concave down. (-00, B): Concave Up (B, 00): Concave Down vQuestion 4 Consider the function f(x) = 12x* + 45x4 -80r + 4. f(x ) has inflection points at (reading from left to right) x = D, E, and F where D is and E is and F is For each of the following intervals, tell whether f(@) is concave up or concave down. (-00, D): Concave Up (D, E): Concave Up E, F): Concave Up (F, o0): Concave Down. Question 5 Consider the function f(x) = 4(x -3)"". For this function there are two important intervals: (-00, A) and ( A, oo) where A is a critical number. A is For each of the following intervals, tell whether f(@) is increasing or decreasing. (-00, A): Increasing (A, oo): Increasing For each of the following intervals, tell whether f(@) is concave up or concave down. (-00, A): Concave Up (A, 00): Concave DownQuestion 6 Consider the function f(r) = c'e f(x) has two inflection points at x = ( and x = D with (