Reducerea la Cadranul I. Trigonometrie. Clasa a IX-a

 

Cadranul II -> Cadranul I

sin (π – x) = sin x

cos (π – x) = -cos x

tg (π – x) = -tg x

ctg (π – x) = -ctg x

Cadranul III -> Cadranul

sin (π + x) = -sin x

cos (π + x) = -cos x

tg (π + x) = tg x

ctg (π + x) = ctg x

Cadranul IV -> Cadranul I

sin (2π – x) = -sin x

cos (2π – x) = cos x

tg (2π – x) = -tg x

ctg (2π – x) = -ctg x