例1求∫x5k 6 解 x,∴x。d 6 6 例2求∫ 1+x 解: (arctan) 1+x I+w2 dx=arctan+C Economic-mathematics 19-6 Wednesday, February 24, 2021Economic-mathematics 19- 6 Wednesday, February 24, 2021 例1 求 . 5  x dx 解 , 6 5 6 x x =         . 6 6 5 C x  x dx = +  解 例2 求 . 1 1 2  + dx x ( ) , 1 1 arctan 2 x x + =   arctan . 1 1  2 = + +  dx x C x