(4) odx=arctan x +C: 1+x 5 dx= arcsinx+C: (6)cos xdx=sin x+ C; n) Istt= sec'xdx=tanx+C xdx=-cosx+c (8) (9) csc xdx=-cotx +C SIn 上页= +  dx x 2 1 1 (4) arctan x + C; = −  dx x 2 1 1 (5) arcsin x + C; (6)  cos xdx = sin x + C; (7)  sin xdx =− cos x + C; =  x dx 2 cos (8)  xdx = 2 sec tan x + C; =  x dx 2 sin (9)  xdx = 2 csc − cot x + C;