∫cosec4xdx=
cotx+cot3x3+c
tanxtan3x3+c
−cotx−cot3x3+c
−tanx−tan3x3+c
I=∫cosec4xdx=∫cosec2x⋅cosec2xdx=∫cosec2x1+cot2xdx=∫cosec2xdx+∫cot2x⋅cosec2xdx=−cotx−cot3x3+c