Question

1)cosx/1-sinx cosx/1 sinx=

2)cosxtgx-sinx=

3)1 tg(-x)/ctg(-x)=

Answer 1

2) cosx*sinx/cosx-sinx=0

3)епч.сепч=sinx/cosx:cosx/sinx=sinx*sinx/cosx*cosx=sin^2x/cos^2x=tg^2x