task/26548414
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4.
5sinα = - 5√(1 -cos²α) = - 5√(1 -( ( 2√6) / 5)² ) = - 5√(1- 24) / 25) = -5*1/5 = -1.
* * * α ∈(3π/2 ; 2π) , sinα < 0 * * *
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5.
24cos2α =24*(1 -2sin²α) =24*(1 -2*(-0,2)² ) =24(1 -2*0,04) =24*0,92 = 22,08.
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6.
10sin6α/3cos3α = 10*2sin3α*cos3α/3cos3α =(20/3)sin3α=(20/3)*0,6 = 4.