来源：学生作业帮 编辑：作业帮 分类：数学作业 时间：2024/07/14 17:29:16
微积分导数小题～
两边求导：
y'=sec^2(x+y)*(1+y')
y'=sec^2(x+y)/(1-sec^2(x+y))=-1/sin^2(x+y)
两边求导：y''=2/sin^3(x+y)*cos(x+y)*(1+y')
=2/sin^3(x+y)*cos(x+y)*(1-1/sin^2(x+y))
=2/sin^3(c+y)*cos(x+y)*(-cos^2(x+y)/sin^2(x+y)
=-2cos^3(x+y)/sin^5(x+y)
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