Below is the graph of a function f(x). (a) Give the x-value of a point where the slope of the tangent line for f(x) is positive. x= (b) Give the x-value of a point where the slope of the tangent line for f(x) is negative. x = (c) Give the x-value for all of the points where the slope of the tangent line for f(x) is zero. x = (separate answers with a comma) 5 1 2 3 0 -5 -4 -3 -2 1 1 2 3 4 5 OT -1 X