★【新教學影片】提要043:認識參數變換法 (Prove that ʃ sec 2x dx = ½ ln|tan 2x + sec 2x|+ C)

★【新教學影片】提要043:認識參數變換法 (Prove that ʃ sec 2x dx = ½ ln|tan 2x + sec 2x|+ C)