分段函数f(x)=当x=1时X*X 在x=1处左导数存在,右导数不存在

x ≤ 1,f(x) = (2/3) x^3 ; x >1,f(x) = x^2f(1)=(2/3)limit[ [f(x)-f(1)] / (x-1),x->1-] 左导数的定义= limit[ [(2/3) x^3 - (2/3) ] / (x-1),x->1-]= limit[ (2/3) (x^3 -1) /(x-1),x->1-] = limit[ (2/3) (x^2+x...