Chapter 0 Preface For general function, its derivative is defined as ∫"(x)≡y df(x) f(x+△x)-f(x) △x->0 The meaning of derivative of a function f(x) tan B A′→)A A △x tangent lim tan B= lin 4y 厂(x) tan a XIx X f(x=tan aChapter 1Chapter 1 Measurment Chapter 0 Preface For general function, its derivative is defined as: x f x x f x dx df x x  +  − =  → ( ) ( ) lim ( ) 0 f '(x)  y' x f(x) x1 x2 A A’   tangent The meaning of derivative of a function: x y   tan  = 1 0 lim tan lim x A' A x x y β   = →  → A'→ A '( ) 1  f x = tan   f '(x1 ) = tan