-x2/2 The normal distribution is defined as f(x) 1 = 21 The following data were generated from the normal distribution: -2 -1.5 -1 -0.5 0 0.5 1 1.5 2. f(x) 0.05399 0.12952 0.24197 0.35207 0.39894 0.35207 0.24197 0.12952 0.05399 Estimate the first derivative f'(x) at x = -1.5 using the three-point forward difference formula with h = 0.5. Compare your result with the true derivative by computing the true error (Et). A f' 0.1875, Et = 0.0115 B f' -0.2179, Et = 0.0419 f' = -0.2618, Et = 0.0198 D f' ~ 0.2834, Et = 0.0414 E f' ~ 0.2272, Et = 0.0329