(2x−10)(x^2−49) не равен 0
тогда
2x-10 не равен 0
2х не равен 10
х не равен 5
х^2-49 не равен 0
х^2 не равен 49
х не равен корень из 49
х не равен 7, х не равен -7
Ответ:[-7,5][5,7]
Sin2α=2sinα*cosα⇒sinα*cosα =(sin2α)/2. sin(π -α) =sinα
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9.
cosπ/9*cos2π/9*cosπ/3*cos4π/9 =(1/2)*cosπ/9*cos2π/9*cos4π/9=
(1/2)*sinπ/9*cosπ/9*cos2π/9*cos4π/9 / sinπ/9=
(1/4)*sin2π/9*cos2π/9*cos4π/9 / sinπ/9=(1/8)*sin4π/9*cos4π/9 / sinπ/9=
(1/16)*sin8π/9 / sinπ/9=(1/16)*sin(π-π/9) / sinπ/9=(1/16)*sinπ/9) / sinπ/9 =1/16.
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10. y =sinx/8 -sin(x/8 -π/2) =sinx/8 -sin(-(π/2 - x/8))=sinx/8 +cosx/8 =√2sin(x/8 +π/4).
T =16π.
* * * sin(x+T)/8 +π/4) =sin(x/8+π/4 +T/8) = sin(x/8+π/4).
T/8 =2π⇒T =16π.
2x²-3x-2/2=x²+x-3/3
x²-4x=0
x*(x-4)=0
x₁=0
x₂=4
2х+6+2х-14=4
2х+2х=4+14-6
4х=12
х=3