Докажите тождество :1/sinb-cosb*ctgb=sinb

Question

Докажите тождество :1/sinb-cosb*ctgb=sinb

Answer 1

1/sinb - cosb.cotgb = 1/sinb-cosb.cosb/sinb=
=(1-cosˇ2b)/sinb=sinˇ2b/sinb= sinb