看 Paul's note 里瑕积分 improper integral 及 comparison test for improper integrals 两部分。
https://tutorial.math.lamar.edu/classes/calcii/inttechintro.aspx
看 session 78, 79,学习计算曲线的长度与曲面的面积。
https://ocw.mit.edu/courses/18-01sc-single-variable-calculus-fall-2010/pages/unit-4-techniques-of-integration/
Gamma and Beta function 的积分
https://www.mit.edu/~jeffery/gamma_beta.pdf
Yuepeng Alex Yang - Integration Bee Topics Guide for Problem Writers,看里面 2.4 Gamma function integral
文档下载点:https://drive.google.com/drive/folders/1g5db9EVWed__aQSDmeyvRcDCHjHjYoyJ
Yuepeng Alex Yang - Introductive Guide to Competitive Calculus
https://www.linkedin.com/posts/yalexyang_introductive-guide-to-competitive-calculus-ugcPost-7374556949142712320-gIGo/?utm_source=share&utm_medium=member_desktop&rcm=ACoAACqZHVEBXDLGGxp-Utxcmgs9xHMQ_TvkR-4
看里面 Integration Bee Training for advanced
https://www.youtube.com/@Silver-cu5up