Упростите выражение (1-sinx) / cosx

(sin²x/2+cos²x/2-2sinx/2cosx/2) / (cos²x/2-sin²x/2) =

= (cosx/2-sinx/2) ² / (cosx/2-sinx/2) (cosx/2+sinx/2) = (cosx/2-sinx/2) / (cosx/2+sinx/2) =

=√2 (1/√2cosx/2-1/√2sinx/2) / √2 (1/√2cosx/2+1/√2sinx/2) = cos (x/2+π/4) / sin (π/4+x/2) =

=ctg (x/2+π/4) или tg (x/2-π/4)