Array ( [0] => Array ( [title] => L21A [link] => https://www.youtube.com/embed/-7FdpGag61M ) [1] => Array ( [title] => L21B [link] => https://www.youtube.com/embed/zio2NzDzIas ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - 第21R講 17.3 The evaluation of double integrals by repeated integrals (Conti.) 17.4 極座標中的二變數函數積分