<span>1/3x - 1 = 4
</span><span>1/3x = 4+1
</span><span>1/3x = 5
х=5 : 1/3
х=5* 3/1
х=15
проверка
1/3 *15 -1=5-1=4</span>
3sin²x - sinx =0
sinx(3sinx - 1) = 0
sinx = 0 или 3sinx - 1 = 0
x=πn, n ∈ Z sinx = 1/3
x = (-1)ⁿarcsin(1/3) + πk, k ∈ Z
<span>1) √3/2sin3x-1/2cos3x=-1
sin(3x-pi/6)= -1
3x-pi/6 = -pi/2+2pi*k
3x=-pi/3+2pi*k
x= -pi/9 + 2pi*k /3
2) sin^2 x-2sin2x-5cos^2 x=0 Делим на cos^2x
tg^2x-4tgx-5=0
D=16+20=36
tgx=5 ->x=arctgx5+pi*k
tgx= -1 ->x= -pi/4+pi*n</span>
Sina-(3*2sina*cosa)/(cosa)-3cos2a+cos3a
sina-(3sin(2a))/(cosa)-3cos2a+cos3a
sina-3*2sina-3cos2a+cos3a
(1-3*2)*sina-3cos2a+cos3a
(1-6)*sina-3cos2a+cos3a
<span>9x-15y+20xy^2-12x^2y=3x(3-4xy)-5y(3-4xy)=(3x-5y)(3-4xy)</span>