12sin44°/sin22°sin68°=12sin(2.22°)/sin22°sin68°=
=12.2sin22°cos22°/sin22°sin68°=24cos22°/sin68°=
=24cos22°/cos22°=24
(sin2α=2sinαcosα , sin (90°-α)=cosα)
16c-12-10c-8
6c-20
с=5\6
6* (5\6) -20=-15
A) sin(π - x) + 2cos(3π/2 - x) = √2/2
sinx - 2sinx = √2/2
sinx = -√2/2
x = (-1)^(n)arcsin(-√2/2) + 2πn, n∈Z
x = (-1)^(n+1)arcsin(√2/2) + 2πn, n∈Z
x = (-1)^(n+1)(π/4)+ 2πn, n∈Z
b) (sinx/2 - 1)*(ctgx + √3) = 0
1) sinx/2 - 1 = 0
sinx/2 = 1
x/2 = π/2 + 2πn, n∈z
x₁ = π + 4πn, n∈Z
2) ctgx + √3 = 0
ctgx = - √3
x = arcctg(- √3) + πk, k∈Z
x₂ = 5π/6 + πk, k∈Z
тока 8 я не знаю как нарисовать график