用介值定理证明积分第二中值定理

Proof of the second mean value theorem by intermediate value theorem

用连续函数的介值性和积分的绝对连续性证明了积分第二中值定理,并用同样的方法证明了当区间为无穷区间时的积分第二中值定理.

We proved the second mean value theorem of integral with intermediate value of continuous function and absolute continuity of integral,and determine that is true even in the infinity interval with same method.