1) (1+ ctg B)^2 + (1 - ctg B )^2 2)tg x + cos x/1 + sin x 3)cos B/1 - sin b + 1-sin b/cos...

Question

1) (1+ ctg B)^2 + (1 - ctg B )^2
2)tg x + cos x/1 + sin x
3)cos B/1 - sin b + 1-sin b/cos B
4) 1 + tg a/1+ ctg a
Помогите

Answer 1

1) (1+ ctgβ)²+ (1 - ctgβ )²=1+2ctgβ+ctg²β+1-2ctgβ+ctg²β=
=2+2ctg²β=2(1+ctg²β)=1/sin²β;
2) 
3) 
4)