题目
若 int f(x)dx = sin x + C，则 int xf(1-x^2)dx = ( )A. 2sin(1-x^2)+ CB. -(1)/(2)sin(1-x^2)+ CC. -2sin(1-x^2)+ CD. (1)/(2)sin(1-x^2)+ C
若 $\int f(x)dx = \sin x + C$，则 $\int xf(1-x^2)dx = (\quad)$
A. $2\sin(1-x^2)+ C$
B. $-\frac{1}{2}\sin(1-x^2)+ C$
C. $-2\sin(1-x^2)+ C$
D. $\frac{1}{2}\sin(1-x^2)+ C$
题目解答
答案
B. $-\frac{1}{2}\sin(1-x^2)+ C$