ctg(90 - alfa)= 2/5 Podaj Sinus cosinus i tangens....

ctg(90⁰ - α)= ²/₅ Wyznaczamy tg α: ctg(90⁰ - α) = tg α = ²/₅ Wyznaczamy ctg α: ctg α = 1/tg α = ⁵/₂ Wyznaczamy sin α i cos α: tg α = sin α/cos α sin α/cos α = ²/₅, stąd wyznaczamy sin α = ²/₅*cosα sin²α + cos²α = 1 (²/₅*cosα)² + cos²α = 1 ⁴/₂₅*cos²α + cos²α = 1 1⁴/₂₅cos²α = 1 ²⁹/₂₅cos²α - 1 = 0 (√29/₅cosα - 1)(√29/₅cosα + 1) = 0 √29/₅cosα - 1 = 0 cosα = 1: √29/₅ = 1*5/√29 = 5/√29= 5√29/29 √29/₅cosα + 1 = 0 (odrzucamy, bo 0<α<90⁰) sin α = ²/₅*cosα sin α = (²/₅)/(5√29/29)=2/√29 = 2√29/29