1. The problem statement, all variables and given/known data In textbook i was given formula to calculate error. I know that: E(t) = f(t)- L(x) = f(t) - f(a)- f'(a)(t- a) [L(x) is linear approximation]; [Lets call this Formula 1] I understand that, but that I have formula: E(x) = f''(s)/2 * (x-a)^2 [lets call this Formula 2] Here I was given Prove that this is correct, by going from formula 2 to formula 1. 2. Relevant equations L(x) = f(a)+f'(a)(t- a) 3. The attempt at a solution I can't connect this 2 formulas to each other logically and i dont want just tu remember (i want to understand it well) P.S. I will attach screenshot if I didnt explain everything.