求不定积分：（1-sect)*tant d(1-sect)

求不定积分∫ (secx)^2/(1+tanx)dx ∫(tant)^5×(sect)^3dt ∫x^3/√(1+x^2 这个不定积分这样做是不是不对,好像从划线那往后都有点问题,还是划线那一步直接可以求出来等于1/sect, 大学解析几何问题曲线r(t)=(0,sect,2tant),t属于[-90,90],绕z轴旋转产生的曲面方程是什么?求该 .高数题 已知函数z=(1/3)ln(x-y),x=sect,y=3 sint 求（dz/dt) | t=π 英语翻译看一个英文材料一句话中提到 Pt.0 Ch.1 Sec.3怎么翻译?是part 0 chapter 1 sect Principle Engineer 、Staff Engineer Supervisor、Executive、Sect 一道很简单的高数积分(1/(x*根号（x^2-1)))dx用换元法令x=sect时为什么要考虑x的符号...tanx和s The village lies across the river-please translate this sect how to do well in school studying is over there fiction sect 高中英语单选helpThe judge told the woman interviewee what key sect ---May I smoke here?---If you ____,choose a seat in the sect 英语翻译Dear PartnerI am the Director in charge of Auditing sect