Question

Решите номера 1-4-3 на листке решите и фото отправьте

Answer 1

1.
sinα = -0,6

cosα = √(1 - sin²α) = √(1 - 0,36) = √0,64 = 0,8

tgα = sinα/cosα = -0,6/0,8 = -0,75

ctgα = 1/tgα = -1/0,75 = -1 1/3

3.
cos²t - sin²t(ctg²t + 1) = cos²t - sin²t( cos²t/sin²t + 1) = cos²t - cos²t - sin²t = -sin²t

Ответ: -sin²t

4.
$frac{(sint+cost)^2-1}{ctgt-sint*cost} = frac{sin^2t+cos^2t+2sintcost-1}{ frac{cost}{sint}-sint*cost} = frac{sint(2sintcost)}{cost-sin^2tcost} =\ = frac{2sin^2tcost}{cost(1-sin^2t)} =frac{2sin^2t}{cos^2t}=2tg^2t$