好久没看数学了,不知道对不对.
f'(x) = -e^(-x)x ln(2-x) + e^(-x)x (1/(2-x)x(-1)+ (1/2)x(1+3x²)^(-(1/2)x 6x
所以求f'(1) = -(1/2e)+(2/3)