Array ( [0] => Array ( [title] => L19A [link] => https://www.youtube.com/embed/YmZTO9bhzsU ) [1] => Array ( [title] => L19B [link] => https://www.youtube.com/embed/1i4EVzynfck ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - 第19講 Roots of Polynomials