Question

用罗尔定理证明f(x)=(x–1)(x–2)(x–3)的导数有几个实根，并指出根的范围

Answer 1

f(x)=(x–1)(x–2)(x–3)有3根1,2,3
用罗尔定理：f'(x)在(1,2) (2,3)各有1根。