3 sinx + cos x/ sin x + 2 cos x = 7 /5; ⇒ 5*(3sin x + cos x) = 7*(sin x + 2 cos x); 15 sin x + 5 cos x = 7 sin x + 14 cos x; 8 sin x = 9 cos x; tg x = 9/8;
1)3 sin^2 x - 2 sin x cos x + 1 = 3 sin^2 x - 2 sin x cos x + sin^2 x + cos^2 x = 4 sin^2 x - 2 sin x cos x + cos ^2 x. 2) 2 cos^2 x + sin x cos x + 3 = 2 cos^2 x +sin x cos x + +3sin^2 x + 3cos^2 x = 3sin^2 x + sinx cosx + 5cos ^2 x.
(x-2)^(x²-6x+8)>(x-2)⁰
1. пусть х-2>1. x>3,
тогда x²-6x+8>0. x²-6x+8=0. x₁=2,x₂=4
+ - +
(2)(4)>x
x∈(-∞;2)U(4;∞)
/ / / / / / / / / / / / / / / /
(2)(3)(4)>x
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
x∈(4;∞)
2. пусть 0<х-2<1, 2<x<3
тогда, x²-6x+8<0
x∈(2;4)
/ / / / / / / / / / / / / /
(2)(3)(4)>x
\ \ \ \ \ \ \
x∈(2;3)
ответ: x∈(2;3)U(4;∞)