Linear approximation Let Δx be a small change in x , then Δf  is the corresponding change in y value which is given as… Δf=f(a+Δx)-f(a) lets use derivative to compute this small change Δf, without computing it directly. By the definition of derivative, When Δx is very small, we have Δf=f ‘(a)Δx  This is the … Continue reading Linear Approximation and Linearization