2. Determine the points on the curve y =-2x* + 5x where the slope of the tangent is -1. 3. Find the values of a and b if f (x) = ax3 + bx' - 5x + 9 and f (-1) =12 and f (-1) =31. The mass, in grams, of the first x metres of a wire is represented by the function f(x) = V3x -2 a) Determine the average linear density of the part of the wire from x =2 to x= 4. b) Determine the linear density at x= 6 and at x= 9, and compare the densities at the two points. What do these values confirm about the wire