Упростите-

1) 1/1+cos a + 1/1-cos a

2) ctg2B (cos2B - 1) + 1

3) tgB+1 / 1 + ctgB

1) ...= ((1-cos a)+(1+cos a))/((1+cos a)*(1-cos a))= 2/(1-cos (a)^2)= 2/(sin (a)^2) или же 2 csc (a)^2

2.1) ...=[(cos 2b)/(sin 2b)]*(cos 2b -1)+1= [(cos (2b)^2 - cos 2b)/(sin 2b)]+1=(cos (2b)^2 - cos 2b + sin 2b)/(sin 2b).

2.2) ctg^2 b (cos^2 b - 1) + 1= sin (b)^2

3) ...=(tg b+1)/(1 + (1/tg b))= (tg b+1)/(tg b+1)/(tg b)= tg b