Show a numerical method for approximating the instantaneous rate of change at x = 3 for the function given by ƒ(x) = - 2x2 + 4x + 1 using slopes of secants.

Answer 1

find f(4), f(3.5), f(3.2), f(3.1), f(3.01)
Now find the slopes of the secants from (3,f(3)) to each of the points.
Watch how it converges to the tangent line at x=3.