Question

Найдите : 1) cosa,tga и ctga ,если sina =12/13
2) sina , tga и ctga, если cosa=0,8
3) sina , tga и ctga если cosa=0,28

Answer 1

Ответ: решение ниже

Объяснение:

1) Дано: sin(a) = 12/13

cos(a) = √(1 - sin^2(a)) = √(1 - (12/13)^2) = √(1 - 144/169) = √(25/169) = 5/13

tg(a) = sin(a) / cos(a) = (12/13) / (5/13) = 12/5

ctg(a) = 1 / tg(a) = 5/12

2) Дано: cos(a) = 0.8

sin(a) = √(1 - cos^2(a)) = √(1 - 0.8^2) = √(1 - 0.64) = √(0.36) = 0.6

tg(a) = sin(a) / cos(a) = 0.6 / 0.8 = 0.75

ctg(a) = 1 / tg(a) = 1 / 0.75 = 1.33

3) Дано: cos(a) = 0.28

sin(a) = √(1 - cos^2(a)) = √(1 - 0.28^2) = √(1 - 0.0784) = √(0.9216) = 0.96

tg(a) = sin(a) / cos(a) = 0.96 / 0.28 = 3.43

ctg(a) = 1 / tg(a) = 1 / 3.43 = 0.29