问题描述: y=ln[f(x)],求y''(1) 1个回答 分类:数学 2014-10-15 问题解答: 我来补答 y=ln(f(x))y'=f'(x)/f(x)y'*f(x)=f'(x)y''*f(x)+y'*f'(x)=f''(x)y''*f(x)=f''(x)-y'*f'(x)y''*f(x)=f''(x)-(f'(x))^2/f(x)y''=( f(x)*f''(x)-(f'(x))^2 )/( f(x)^2 )y''(1)=( f(1)*f''(1)-(f'(1))^2 )/( f(1)^2 ) 展开全文阅读