题目
int_(0)^(pi)/(3) x cos 3x , dx = ____A. (2)/(9)B. -(2)/(9)C. (1)/(9)D. -(1)/(9)
$\int_{0}^{\frac{\pi}{3}} x \cos 3x \, dx = \_\_\_\_$
A. $\frac{2}{9}$
B. $-\frac{2}{9}$
C. $\frac{1}{9}$
D. $-\frac{1}{9}$
题目解答
答案
B. $-\frac{2}{9}$
A. $\frac{2}{9}$
B. $-\frac{2}{9}$
C. $\frac{1}{9}$
D. $-\frac{1}{9}$