(1 1/5+2 3/10): 1/2+(6 3/4-2 2/3): 1 1/6 это дробь. решить по действиям. пожее

Question

Математика: (1 1/5+2 3/10): 1/2+(6 3/4-2 2/3): 1 1/6 это дробь. решить по действиям. пожее

suleimanzhasulan · Accepted Answer

Task/24970505

arccos(-cos(-43π/6) ) - ?

cos(- 43π/6)=cos(43π/6)=cos(6π +π+π/6) =cos(π+π/6) = -cos(π/6) = -(√3)/2.
arccos(-cos(-43π/6) )=arccos(√3)/2 ) = π/6 .

ответ : π/6 .

формулу arccosa +arccos(-a) =π , |a| ≤ 1 не использовал

sin(16π/3) = sin(4π+π+π/3) = sin(π+π/3) = -sin(π/3) = -(√3)/2 ;
arcsin(sin(16π/3) = arcsin(-(√3)/2) = - π/3 ;
arccos(cos(-15π/8) )=arccos(cos(15π/8) )=arccos(cos(2π -π/8) )=
arccos(cos(2π -π/8) ) =arccos(cos(π/8) ) = π/8

35*arccos(-cos(-43π/6) ) /(arcsin(sin(16π/3)+arccos(cos(-15π/8) )=
35*(π/6) / ( - π/3+π/8 ) =(35π/6) / (-5π/24) = -28 .

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