+55
2 года назад
Алгебра
5 - 9 классы
[tex]frac{cos(x)cos(y)-cos(x+y)}{cos(x-y)-sin(x)cos(y)}=[/tex]
[tex]frac{cos(x)cos(y)-cos(x)cos(y)+sin(x)sin(y)}{cos(x)cos(y)+sin(x)sin(y)-sin(x)cos(y)}=[/tex]
[tex]frac{sin(x)sin(y)}{cos(x)cos(y)}=tg(x)tg(y)[/tex]
[tex]frac{cos(x)cos(y)-cos(x+y)}{cos(x-y)-sin(x)cos(y)}=[/tex]
[tex]frac{cos(x)cos(y)-cos(x)cos(y)+sin(x)sin(y)}{cos(x)cos(y)+sin(x)sin(y)-sin(x)cos(y)}=[/tex]
[tex]frac{sin(x)sin(y)}{cos(x)cos(y)}=tg(x)tg(y)[/tex]