Ishoralar va asosiy munosabatlar
Javoblar ota-onalar va o‘qituvchilar uchun.
1
α = 4π/3 uchun sin α, cos α va tg α ishoralarini aniqlang.
sin α < 0, cos α < 0, tg α > 0 (III chorak)
2
1000° burchak qaysi chorakda yotadi va sin 1000° ning ishorasi qanday?
1000° = 2 · 360° + 280°, IV chorak; sin 1000° < 0
3
cos α = 12/13, 3π/2 < α < 2π bo‘lsa, sin α ni toping.
−5/13
4
tg α = 3, 0 < α < π/2 bo‘lsa, cos α ni toping.
√10/10
5
1 + tg²α = 1 : cos²α ayniyatni sin²α + cos²α = 1 dan keltirib chiqaring.
Ikkala qismini cos²α ga bo‘lamiz: tg²α + 1 = 1 : cos²α.