用对数求导,y=(根号x+2(1-2x)^2)/(x+3)^4 要正确的,追分

lny=(1/2)[ln(x+2(1-2x)²)-ln(x+3)^4]
lny=(1/2)[ln(x+2(1-2x)²)-4ln(x+3)]
y′/y=(1/2)[(1-8x(1-2x))/(x+2(1-2x)²)-4/(x+3)]
y′=y(1/2)[(1-8x(1-2x))/(x+2(1-2x)²)-4/(x+3)]
y′=(√(x+2(1-2x)^2)/(x+3)^4))(1/2)[(1-8x(1-2x))/(x+2(1-2x)²)-4/(x+3)]