sin a = 1/3 sin²a+cos²a=1 (1/3)²+cos²a=1 cos²a=1-1/9 cos²a=8/9 cosa=√8/9 cosa=2√2 / 3 tga= sina/cosa tga=1/3:2√2 / 3 tga=1/3*3/2√2 tga=1/2√2 tga=√2/4 ctga=4/√2=4√2/2=2√2
sin a=1/3 sin2 a+cos2 a=1 cos 2 a=1-sin2 a cos2 a=1-1/9 cos2 a=8/9 cos a=2pierw z 2/3 tg a=sin a/cos a tg a=1/3:2pierw z 2/3 tg a= 1/3 *3/2pierw z2 tg a=pierw z 2/4 ctg a=cos a/sin a ctg a=2 pierw z 2 /3 :1/3 ctg a=2 pierw z 2/3 *3/1 ctg a=2 pierw z 2
Dane: sinα = 1/3 cosα = ? tgα = ? ctgα = ? sin²α + cos²α = 1 (1/3)² + cos²α = 1 cos²α = 1 - 1/9 cos²α = (9 - 1)/9 cos²α = 8/9 cos²α - 8/9 = 0 (cosα - 2√2/3)(cosα - 2√2/3) = 0 cosα - 2√2/3 = 0 ∨ cosα - 2√2/3 = 0 cosα = 2√2/3 ∨ cosα = - 2√2/3 tgα = sinα/cosα tgα = 1/3:( 2√2/3 ) ∨ tgα = 1/3:( - 2√2/3 ) tgα = √2/4 ∨ tgα = - √2/4 ctgα = 1/tgα ctgα = 1/√2/4 ∨ ctgα = - 1/ √2/4 ctgα = 2√2 ∨ ctgα = - 2√2
