題目
Problem
甲、填充題:共 8 題,每題 8 分,共 64 分。請在答案卷上列出題號依序作答。
- Suppose f′′ is continuous on [0,1], f(1)=2, f′(1)=2 and the average value of f on [0,1] is 2. Evaluate ∫01x2f′′(x)dx. Answer : \underline{\quad(1)\quad}
解答
解法一
兩次分部積分並用 ∫01f(x)dx=2:
∫01x2f′′(x)dx=[x2f′]01−[2xf]01+2∫01f(x)dx=2−4+4=2.