# Question: use a forward difference and a centered difference approximation to...

###### Question details

Use a forward difference and a centered difference approximation to estimate the first derivative of the function: f(x) = 20x4 - 4x3 + 3x2 + 6x - 49. Evaluate the derivative at x = 1 using a step size of h = 0.2 (that is, xi+1 = 1.2, xi = 1, and xi-1 = 0.8). Compare your results with the true value of the derivative and compute the true percent relative error t.