<span>1) cosX=-1
x=</span>π+2πk,k∈z
<span>
2) sin2X=√3/2
2x=(-1)^k*</span>π/3+πk
<span>x=(-1)^k*</span>π/6+πk/2,k∈z
<span>
3) 3ctg X/3=√3
ctgx/3=</span>√3/3
<span>x/3=</span>π/6+πk
<span>x=</span>π/2+3πk,k∈z
<span>
4) 2sin(X/2+П/8)+√2=0
sin(x/2+</span>π/8)=-√2/2
<span>x/2+</span>π/8=-π/4+2πk U x/2+π/8=-3π/4+2πk
<span>x/2=-3</span>π/8+2πk U x/2=-7π/8+2πk
<span>x=-3</span>π/4+4πk U x=-7π/4+4πk,k∈z
<span>
5) (1+cosX)(3-2cosX)=0
1+cosx=0
cosx=-1
x=</span>π+2πk,k∈z
3-2cosx=0
cosx=1,5>1 нет решения
( х-2)(х+3)>=0
ООФ (-бескон, - 3]U[2;+ бескон)
Sn=2а×1+(n-1)×d×n÷2 S10=2×(-1)+(n-1)×10/2 S10=-2+9×3×5 S10=105,d-разность данной арифметической прогресси
х+12=3х -7-х=3х+17 3(х-3)=х+2(х+5) <span>-4(х+2)+3(х-1)-2=4(х-2)+9</span>
х-3х=-12 -х-3х=17+7 3х-9=х+2х+10 -4х-8+3х-3-2=4х-8+9
-2х=-12 -4х=24 3х-х-2х=10+9 -4х+3х-4х=-8+9+8+3+2
2х=12 х=24/(-4) х=19 -5х=14 |:(-5)
х=12/2 х=-6 х=14/5
х=6 х=2 , 4/5
Или (7/8-4)×8
(-25/8)×8
-25