Question

函数fx在［-1,1］可微,f0＝0,｜f'x｜＜M,

Answer 1

证明：f(x)=f(0)+f'(u)(x-0)=xf'(u),其中u介于0与x之间.

|f(x)|=|x||f'(u)|,

由于|x|