1) 2 sin x + 1 = 0
2 sin x = -1
sin x = -1/2
x = (-1) ^ n * (- п/6) + пn
2) tg (3x - п) = 0
3x - п = пn
3x = пn + п
х = пn/3 + п/3
3) 2 cos x + √3 = 0
2 cos x = - √3
Cos x = - √3/2
X = ±5π/6 + 2πn
4) 2 sin 2x = √3
Sin 2x = √3 / 2
2X = (-1)^n * π/3 + πn
X = (-1)^n * π/6 + πn/2
5) sin x - √3 cos x = 0
2 sin (x- π/3) = 0
Sin (x - π/3) = 0
X - π/3 = πn
X = π/3+ πn
6) tg 2x = 1
2x = π/4 + πn
X = π/8 + πn/2
7) 2 sin x = 1
Sin x = ½
X = (-1)^n * π/6 + πn
8) 8 sin ^ 2 x – 10 sin x – 7 =0
Замена sin x = t, -1 ≤ t ≤ 1
8 t^2 – 10 t – 7 =0
D = 100+7*8*4 = 324
T1 = (10 + 18) / 16 = 28/ 16 = 7/4 – не удовлетворяет условию замены
T2 = (10 - 18) / 16 = -8 / 16 = -1/2
Обратная замена:
Sin x = -1/2
X = (-1)^n *(-π/6) + πn
9)4 sin 2x + 10 cos 2x = 1
2 √29 sin (2x +arctg 5/2) = 1
sin (2x +arctg 5/2) = 1 / 2 √29
2x +arctg 5/2 = (-1) ^n * arcsin (1 / 2 √29) + πn
2x = (-1) ^n * arcsin (1 / 2 √29) + πn - arctg 5/2
X = (-1) ^n * arcsin (1 / 2 √29)/2 + πn/2 – (arctg 5/2) / 2