text: ap calculus help? the figure above shows the graph of f’,the derivative of a function f the domain  of f is the set of all real numbers x such that - 10 < x <10. (a) for what values of x does the graph of f have a horizontal tangent?  (b) for what values of x in the interval (- 10, 10) does f have a relative maximum?  justify  (c) for what values of x is the graph of f concave downward? (a) the values when f'= 0. (b) look on the graph at all the points were f'=0 and see if the corresponding points on f are a max, min or point of infection (like on x^3) (c) when the values of the f'' are negative (the second derivative