1+cos2、λ,x [cos a,x]'dx dx=2+cos2√nxx 0 sn2√,x sIn 2 2sin√ 2.l cos√Al sIn lcot√ X vAn cot2√λ,l+122x,h2+1 cot√x h cot√=h√ 1-cos2√n sn√nxax= 0 2 224h2+12 1 1 cot 1 2 cot 2 1 2 sin cot 2 1 2 2sin cos 4 1 2 sin 2 4 1 2 sin 2 4 1 2 cos 2 2 1 2 2 1 cos 2 [cos ] 2 2 2 0 0 0 0 2 2 + = + + = + = + = + = + = + = + + = =    h l h l l l l l l l l l l l x l xdx l dx x N x dx n n n n n n n n n n n n l n n l n l n l n n                  2 1 1 2 2 1 cos 2 [sin ] 2 0 0 2 + = − − =   h l h dx x x dx n l n l n    cot   l h =