Array ( [0] => Array ( [title] => L14A [link] => https://www.youtube.com/embed/LC8fBYW9R-E ) [1] => Array ( [title] => L14B [link] => https://www.youtube.com/embed/2WyYn6FqjkI ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - 第14R講 The Tangent Plane and the Differential of a Map (cont.)