1)cos2x-cosx-1=0
2)sinx-1/cosx=0

Ответ:

1. cosx = cos2x-1

2. sinx = cosx+1

Объяснение:

1. cos2x-cosx-1=0

cos2x = cosx+1

cosx = cos2x-1

2. sinx-1/cosx=0

cosx = sinx-1

sinx = cosx+1