(d) Give the local maximum and minimum values of f (a). Enter your answers in increasing order of the x-value. If there are less than two local extrema, enter NA in the remaining response areas and the corresponding drop-down menu. Include a multiplication sign between symbols. For example, a . IT. f( X ) = 0 NA f( X )= 1 NA (e) Give the intervals of concavity of f (z). Note: Use the letter U for union. To enter co, type infinity. If the function is never concave upward or concave downward, enter NA in the associated response area. concave upward: (-infinity, -1) concave downward: (-1, infinity) (f) Give the inflection points of f (x). Enter your answers in increasing order of the x-coordinate. If there are less than two points of inflection, enter NA in the remaining response areas. Include a multiplication sign between symbols. For example, a . IT