用对数求导法怎么做?[IMG]http://i51.tinypic.com/169fdvk.jpg[/IMG]

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/04 23:52:34
用对数求导法怎么做?[IMG]http://i51.tinypic.com/169fdvk.jpg[/IMG]

用对数求导法怎么做?[IMG]http://i51.tinypic.com/169fdvk.jpg[/IMG]
用对数求导法怎么做?
[IMG]http://i51.tinypic.com/169fdvk.jpg[/IMG]

用对数求导法怎么做?[IMG]http://i51.tinypic.com/169fdvk.jpg[/IMG]
y = [(3-x)^4√(x+2)]/(x+5)^5
lny = ln[(3-x)^4√(x+2)]/(x+5)^5
= 4*ln(3-x) + 1/2*ln(x+2) - 5*ln(x+5)
【取对数求导法:[lny]'=y'/y ==> y'= y*[lny]'】
y' = y*[lny]'
= [(3-x)^4√(x+2)]/(x+5)^5 * [ 4*ln(3-x) + 1/2*ln(x+2) - 5*ln(x+5)]'
= [(3-x)^4√(x+2)]/(x+5)^5 * [ -4/(3-x) + 1/2(x+2) - 5/(x+5)]